Imo support is one of the best roles I dont find it a 50/50 role as you say it is its the easiest role in the game.
Not all support champions and the player itself need to buy a sightstone early. If im playing tahm kench I have move speed, armour and 7.5% cd on my runes and masteries even about to 13% cd if i use the intelligence mastery, you can just easily take your adc out of danger with zero effort.
If your adc pays attention (or your premade) you can use thresh, we all know how annoying it is when some people dont take a thresh lantern.
Still most support players should still buy a sight stone but there are some times where it wont be needed but thats my opinion and mine can be countered by some really good arguements.
Obviously will buy one or two control wards, im not a jerkoff so i will buy some wards XD.
Keep in mind i respect the meta of support but at the same time as a support main you should break the meta (pretty much like anyrole) aslong as it has a benefit to the team... so no silly things like support singed, udyr.
I did a few games this season and just quit. Some of my friends who are still climbing (three in plat now) they tried to convince me to ignore autofill but its so annoying to deal with it especially if your allies in SoloQ threaten to troll because they dont want to play a role they got assigned to. Untill later this year when more mature gamers play league or if autofill gets removed then i will return to ranked but for now. NOPE.
You dont have to hammer the information down on me I know about support items but to be honest i do wish there was an AD version but from some of my friends who main lee sin and riven it would be a pretty frustrating thing for some bot laners to deal with. There are 3 other AD tanks i play on support sometimes and thats Kled, Teemo, Sion.
With teemo say what you will about him i dont care but his mushrooms are basicly wards and with a frozen mallet and black cleaver (i know you can't use his abilities to shred armor but only auto attacks but thats not a problem if you know how to position.
Kled is an odd one I wont go too much into detail but well obviously he can't give vision whcih is a kick in the go-nads but he can catch up to all adcs with no problem with possible acception of ezreal. Get a tiamat then if your being fair get a sightstone if you wish or just get black cleaver or a trinity force then go to town.
Sion, He is so much fun to play and it baffles me that Sion's invisible Q in brushes is still not patched out, You can build sion almost anything with AP, AD with HP or just full tank.
Sorry for tldr but i like to explain or share information with others regardless of the person.