I think it would be fine to be able to administer a healing potion to a stabilized ally by walking next to them and using an action. That ally should already be stabilized though. Letting someone gets down in combat should be punishing. The stakes are so low with the current system that the tension in combat is completely undermined.
I'm fine with forcing a potion down an unconscious
and dying ally's throat. It's magical healing and thus reasonable to bring them back to consciousness that way. The action
+ movement + consumable cost is high enough that it doesn't step on other classes' toes too much or make it too powerful, and pouring it down their throat as an action is realistic enough.
