His Q is pretty much always "JUST DO IT", whether it be minion, monster, or champion that's in his range.
Well, yes, it's not the most intensive of skills in terms of decision-making requirements or micro, but considering that (you at least) admitted that WER are fair abilities that do require decision-making (although the damage amp on R has proved time and again to be an issue for balance and IMO needs to be removed at this point), that's 3/4 abilities that are fair. That's pretty good if you ask me.
I just remember his plethora of nerfs following his update, along with some minor buffs
Yeah, MYMU-patch Vlad had a passive that made full-tank builds ludicrous. I used to rush DMP and Spirit Visage and still output big damage. That was nerfed, then he had some more HP ratio and base damage nerfs, then got some AP buffs.
resourceless drain tanks
I figured that refers to costless, CDless ADCs with lifesteal, rather than Champions who are a) designed around sustain and b) still have to deal with cooldowns or melee-ness. That might be my interpretation being wrong, but Vladimir also has not-ignorable costs on the rest of his kit, as you yourself has pointed out.
Grievous Wounds itself is partially a problem for what it is at it's core, but the main issue is how it's applied. There are three itemization methods of GW, the most accessible of which simply adds it to your AAs, meaning there is fuck all you can do about it when the ADC starts rightclicking on you. If it was on a cooldown, or was an active like BotRK, it'd be much more reasonable to deal with as a healer, and then you could amp the value of the anti-healing so that in the sparse moments of when the GW is active, it's really worthwhile.
Because my ideas would be bad, and I should feel bad.
Well that's being unfair to yourself, and if you expect to have bad ideas you're more likely to have bad ideas. I'm sure in a discussion about Ahri or one of your other favourite Champions, your ideas would be better since you have better experience and insight.
...That being said, what you've suggested are straight nerfs, rather than the power-shift we need, and nerfs isnt what Vladimir's Q needs.
"Change it to basically old spellvamp to heal based on damage dealt, lowering his reliable heals if he has to Q the Tank."
That just makes life hard for the Vladimir player, since you shouldnt have to gauge how much health you're healing for per target.
Q only heals off of Champions and Epic monsters." or "Q's CD is increased if used on a non-Champion or non-Epic monster"
Basically just remove Vladimir from the game. That's like if you doubled mana costs for all skillshots if they miss Champions.
Something I might suggest, but am hesitant to do so because Transfusion needs to be reliable, is that they "Veigar" his Q. Remember when they changed Veigar's Q from point-click to a skillshot, but the tradeoff is that it now has higher range and can hit two units?
Of course, because of the way Transfusion works it'd have to be backwards, starting at a cast-point and moving towards Vlad.
But that's the only thing I can think of and be confident with, and even then it's iffy.