Some general Runes feedback
Resolve should have been split in two trees.
Resolve is the defensive tree, and because every row has to provide something for every class that wants some extra defences. This includes all bruiser classes, and all the tank classes. The result is a tree with minimal options for every class (especially for key-stones) and bland runes. Juggernauts take Grasp, Vangaurds take Aftershock, and Wardens take Gaurdian, as each of them have no other option.
Splitting them in two different trees would allow a more diverse option of runes for both of these classes, and any other class that would like to pick up some extra defences for that matter. One tree should focus on Juggernauts and Vanguards, the more offensive tanks/bruisers, build around some extra damage, stickinish, sustainablity, and health as defensive stat with Keystones like Grasp and Aftershack.
The second one should focus more on the Wardens and Peelers, the really defensive classes, build around protecting your team members, peeling and general defences. Their defence should focus more on resistances to make a different with the other tree, with their runes providing allied defences (Like the Gaurdian Keystone, and Revitalize/Font of Life smaller runes), peeling abilities (Like extra slows for example) and just general defences.
Inspiration tree is a fun idea, but just doesn't seem very appealing outside of certain 'exploit' cases.
The only champion I have seen so far that has taken inspiration as their main tree is Ezreal with Kleptomancy, as his Q will activate the rune. Looking at the runes I can completely understand this, as all three runes are just to situational, where for some I'm even wondering who would want to use these in what situation.
Unsealed Spellbook allows you to change your summoners. The only two cases I could see this being valuable is for an offensive support changing ignite to exhaust after laning phase, and an aggressive Top laner changing ignite for teleport. But both in these cases, they would most likely be better of taking a different keystone, and stick with their ignite or not take it all together, as other keystones just provide much more value. Especially if you are playing an aggressive support or top laner, you will most likely need the extra damage from one of the other runes to really cement an early lead.
Glacial Augment seems to be ment for engagers that want some extra stickiness. To me it just seems a bit overkill on providing extra slows; If you already engaged the enemy you most likely locked him down, or at the least slowed him down. You don't need more slows. Especially the freezing ray part just seems overkill; They are already slowed, why would you need more slowing ground? It doesn't help against the enemy just dashing away from the slowing ground as well, which is the main weakness of engages that mainly rely on slows.
Kleptomancy is just an exploit rune. If you can use it effectively like Ezreal can, you can get large laning advantages with extra gold, and free potions, wards and elixers. It's a fun keystone for sure, but outside of Ezreal and maybe GP extremely situational and RNG based.
The smaller runes consist of some good ones, and some bad ones. Perfect Timing, future market, Cosmic Insight, and Celestial Body are all good situational runes, with stuff like providing a free Zhonya item against certain all-in match-ups (Mainly against Zed), the possibility to go in debt for earlier buyes, extra CD + higher cap, and flat 100 extra health without any negative effects after 10 minutes.
The rest just feels a bit underwhelming in what they really provide; Biscuits that are only effective if you are low on health (where you most likely are going to back anyway), 10% movement speed towards CC'ed enemies/allies, easier last hitting, or a small flash with 2.5 seconds cast time for creative gank pathing. All of them are just to situational, with a couple even feeling pretty useless altogether.
Overall inspiration tree just feels a mess, with a combination of left over ideas and filler runes. The only Keystone that is seeing play regulary is on 1 champion that can really exploit it. Some of the smaller runes aren't that bad for the secondary tree choice, but as a main tree it just doesn't offer enough.
The stat bonus from rune trees should depend on both trees.
One reason why damage seems so out of control is the lack of early game defensive stats. If the bonus for runes tree (the flat stats you get from just choosing your main tree) would be a combination of both the main and second tree, you could chose a defensive secondary tree to get some extra defensive stats. The main tree should provide more stats, then the second tree.
An example to make it better clear; Sorcery + resolve would give 10 AD/15 AP + 80 health, instead of the current 15 AD/25 AP. Turning it around and going Resolve + Sorcery would give 120 health + 6 AD/10 AP.
In this case choosing a defensive tree as a secondary will provide valuable early game defences, when you are facing a harder lane. Something that is not possible in the current system, without the need to chose
Adaptive damage really seem to favour AD champions.
With this I don't mean the adaptive scaling, but abilities that can deal or AP or AD damage, depending on what will deal the most damage. This favours AD champions more then AP champions in my opinion, as the abundance lethality options compared to magic penetration options, allows AD champs to make better use of the basic stats on these abilities. This is the clearest noticeable in how much extra burst AD champions can get from Electrocute keystone, especially when compared with the sudden impact minor rune. A lot of champions, like Nocturn, Jarven and Lee, can kill you with 1 full combo after level 6 with sometimes nothing more then a Serrated Dirk for damage items.