No. 4 second long animation will cause healing to only be used outfight, as probably no one can manage to have a 4 second long window with no damage coming in at all… (Assuming that taking any damage or sprinting or climbing would cancel the healing animation.)
As for managing stamina… Whoever wastes all his stamina is as good as dead in pvp, as he serves himself to his enemy. That takes like 4 or 5 seconds as well.
Yet again: once any weapon or tool is being equipped, I can not use bandages. Also I lose the healing effect of bandaging on any damage that I get dealt. (Even on climbing, for whatever reason.) If receiving damage wont abort that healing, its probably a bug. (or live version, which disqualifies itself from that healing discussion anyway)
Also you are forgetting about pve… yet again.
And no, exploiting bad AI isnt an option for me there.
There are enough monsters and creatures which still hurt even with lvl 60 and black keep armor. Eating away 50 HP or rather more with each hit. Not everyone likes to roll around all the time (or is able to).
And no. Limiting players to one or two playstyles (like exploiting with bow or using full defense, meaning wielding a shield) is no option as well.
Pvp seems to be the only thing in your mind, and you seem to be pretty much limited in your ideas on how to fix this healing issue in pvp. Even worse, you wont even react to a anti-healing-poison-idea. Instead, you want to render healing almost inviable during combat. Even changing the healing from flat 20% or even maybe 50/100 HP healing to 20% of lost HP would have been an option. Or else. Get creative! Dont stick to plain MMO-law-cooldowns and animations for a game where half or even a quarter of a second can decide on wether you die or win.