Buffing your heal would not solve the problem of you having to pick up potions that are in the end useless and will just be thrown away after being picked up for the buff. I don't think it would make the game imbalanced. I'd say it would have no impact at all. Many of my characters don't even have to pick up health globes anymore on T6 because everything dies too fast, let alone needing to drink potions or gaining buffs on those potions. The place where such a buff could be useful, would be GRifts, where no potions drop anyway and you cannot even tamper with your inventory to drop potions for yourself. Sorry, but I don't think that would be a good design.
I'd say the best way to use potions would be to make them a crafting materiál for some rare dyes or something. Just make some 50-odd different shades of the dyes that already exist in game (with previews so we know what we're getting) and let us customize a bit more. They would still become irrelevant once you've made a decent enough supply of the dyes for yourself but they would at least be somewhat useful once in a while, which is the polar opposite of what they are now (completely useless, all the time). Legendary potions will always become the one thing you will be using once you get it, so I think healing potions should find an alternative role outside of the healing area.