Current Runes and adc/tank/support items balancing ideas
Currently, adc items feel too cost efficient and runes give out too much damage. This is the way I would balance some of it not most of them.

costs 200 more, from 3400 to 3600.
costs 100 more.
all cost 200 more. This with the infinity edge should reduce how quickly adcs get to their power spike.
now no longer has cdr. This could help fix the issues with how maokai has perma cc and other champs that use it extremely well.
should have base shield amount lowered from 38 (+22 per level) to 38 (+ 20 per level). Lowering it to 18 could be better but it's hard to tell how much of a nerf this would impact.
should have a weaker passive on the shields/heals. I would nerf it to 8% from 10%.
should get a 2% heal/shield nerf since the completed item is getting a nerf.
should get a 2% heal/shield nerf.
I believe this item should cost 100 more and give 10 more ap.
the lethality should be decreased by 2 and the damage should be decreased from 65 to 320 to 55 to 280
lethality should be reduced by 2
lethality should be reduced by 2, maybe add like 5 mr to this item but I don't know, I barely see anyone use it tbh.
lethality should be reduced by 2
her Q bonus ad ratio should be increased from .8 bonus ad to 1.0 bonus ad. This is just for build diversity sake, it won't change her full tank build and it won't really be a huge buff else where.
should get a rework since his kit is extremely frustrating to play again. I think they should rework his ult and make it remove its base damage and make his e ad ratio do increased damage. Another idea is to make his ult make his passive do more damage than it originally does.
Also, a few top lane tanks will probably need small nerfs to make the top lane role have more diversity.
Other changes I think could be good if the adc role is still too strong is to nerf
and
damage by 5.
Now, onto the runes. Starting off at the domination tree, electrocute will probably need a small nerf. If the rune itself feels too weak in lane, buffing the cdr itself will probably help fix this issue. Predator should get a cdr buff. It is supposed to helps ganks and stuff, but currently it feels too focused on the damage burst then the actual ms. So, buffing the ms and nerfing the damage by a little should help fix this. I don't have any thoughts about dark harvest right now, but I feel the keystone design is a little flawed. This keystone will either be too strong in certain games where you have a lead, or way too weak where your team is behind and it feels like you have no keystones. I don't know how to fix It honestly and I don't think it's op or too weak, but it's too feast or famine as a keystone right now.
The next row in domination feels too strong. It's ok if there is a row of runes to be strong, but this 1 has like half of the effectiveness of the actual keystone itself. Sudden impact cooldown should be increased by 4. This keystone only have a cd of 4 is actually making it too strong in lane I think. It also needs a nerf in lethality by 2 and magic pen by 2 (I know It's 10 lethality and 8 magic pen, but having 7 magic pen compared to 10 lethality would seem too strong on the magic pen side of things compared to ad). Taste of blood I think is rather balanced, but to keep the other 2 runes in line with this rune, it should have a 5 cdr nerf (to 25 cd, from 20) This rune could have a small ap/ad ratio to compensate for this nerf, though. I think cheapshot is rather balanced I think but adding 2 cd to it could balance it out better. The next row of runes honestly feel a little weak, but I think they are balanced currently. This next row, honestly, feels either meh on certain champs, or completely broken on others (hello supports item cd, and hello certain champs who use the ability heal really well like swain and ryze I think). I feel like this row should be reworked to become similar to the ones in the precision tree. It's hard to say how to do a direct buff/nerf to it but the way this row is placed makes it way too feast or famine. This row will either be insanely broken, or almost useless. After it gets changed, then they will probably need a nerf to compensate for how much easier it will be to get.
So, the precision tree has a little too much damage right now from what I can see. In the keystone row, press the attack is currently dominating the choices. There is like no reason to go lethal tempo and fleet footwork on most champs compared to how good press the attack is. I think that press the attack should get a nerf on it's 3rd proc damage per level in the early game, but scale up to the same late game. Basically, nerf it in the 1-11 lvls and buff or stay the same at 12-18 lvls. The 12% damage amp is also a little dumb but I think that It either should be only 10%, or it should be 12% but only for the target who procs. Lethal tempo is getting buffed next patch, which I think is tomorrow, and so is fleet footwork. Personally I think fleet footwork should be like 20-30% effective on crits, and not 40%. However, the ad and ap buffs to it is going to help the keystone feel like it has a place in the game (I just don't want to return to the every adc takes warlord because it's the best keystone like last season). Triumph should get nerfed, pretty hard. It currently feels like the only keystone you should take on that row. Imo, it should get a 5% missing hp nerf. It should also get a gold nerf. I believe that triumph should reward you 20 gold (down from 25) for each kill you get, and 10 for each assist. Overheal is getting a buff I believe so we need to wait and see how good it will be compared to triumph (the triumph nerf in the patch notes, not here). presence the mind I honestly think is a little weak. It is getting a buff I think in the patch notes but the rune itself feels like it has very limited uses. I think that this next row is rather balanced. It might needs nerfs on how fast you get it in the jungle, but I think it feels balanced. Maybe this is biased since I love the atk spd from alacrity on poppy but it's hard to really nerf it when the numbers are a little low. Coup de grace is currently too strong. It should get a nerf to either 8% while removing the addition after kill passive or it should get nerfed to 7% and keep the after kill passive. I think that cutdown should get it's first max health passive increased from 150 to about 400. This will only make the rune feel only useful against tanks, and not just someone who decided to pick up a 150 or so hp item. The first passive should get nerfed from 4% to 3.5% damage and the 2nd passive should be reduced from 10% to 8%. Last stand Should probably get a nerf that is similar to cutdown. I personally think that both these runes are balanced in the row but percentage damage does put in more of a damage creep to the game. I would say last stand's nerf should be reduced to 4% to 10%, however, the amount of hp the maximum damage actives should be increased to 40% from 30%. This just allows it to be useful on more champs than just people like mundo.
The **sorcery **tree has a few unbalanced runes but a lot of the runes I think are balanced. I personally do not know how much the base ad type of runes have an impact on the game. The first keystone, summon aery, should get another small early game nerf. I think the cd should be increased by 1s. This is mainly to nerf the dot mages (looking at you, malzahar and teemo). I think comet is balanced at mid lane, but it is too strong at top lane, specifically tanks. currently, comet does 30-100 base damage with 0.2 ap ratio and 0.35 ad ratio and also a cd of 20-8s. I think comet should have a 5 damage nerf (so 25-95). It could potentially need a 10 damage nerf but I'm not entirely sure about it yet. It should probably also have a cd buff at late game from 20-7s. I think phase rush should only uses 2 auto attacks and not 3 auto attacks for melees. The buff to slow resist that riot has on this keystone I believe is fine. The next row in general, seems a little strong. it's fine for it to be strong but manaflow band in particular is busted right now. This rune, needs a 2-3% missing mana restore as a nerf. I think the other 2 runes is fine. I don't have any experience as a mid laner, especially vs ad assassins, so I don't know how strong nullifying orb is right now. The next row I think is balanced except for celerity which is getting a nerf. In the last row, scorch is the 1 that stands out as being busted, especially I think on top lane and support. This probably needs a 10 base dmg nerf, so from 30 to 20. It also should scale up a bit better, so from 60 to 65. In the resolve tree, I think this tree is the most balanced right now. The only nerf I would want is on aftershock. a .5% maximum health nerf on the damage could help to put it back to being balanced. It might need a little more nerfs but only time will tell.
The inspiration tree is also quite balanced. The only real rune that stands out for me as being broken or op is kleptomancy. This rune, needs to have elixir of skill to be taken out. This keystone also needs to get a nerf on like every single potion. it probably needs like 10-30 hp/mana potion nerfs and like 5-10 damage nerfs on the other damage type elixars. I honestly don't know how many elixars there are but I do know that this keystone is broken. Another nerf could be the amount of gold you get from the gold backs. It could get a nerf by 20. There are a few runes in the inspiration tree that are too weak like minion dematerializer that will need buffs but they take longer to test and it's honestly hard to really come up with a buff/nerf for them on the spot :P. And also, every single champion except mages should get a 5 magic resist buff and mages should get a 5 armor buff. I understand about spell pen, but this spell pen was maxed out at like 8 to 10. I honestly forgot the exact amount but we lost too much mr, so specifically champions who didn't go spell pen are currently wrecking lanes. Not all of them are, but a lot of them are op.
tldr:buff/nerfs of items are at the top, and nerf to the runes are at the middle of the page to the bottom.
Anyway guys, thanks for reading for anyone who read this and give a comment below if you agree, disagree, or what you think about the current situation with this preseason :).