I thought cards in hand was the theme. This looks like it plays much better with the rest of the set, but it also looks at first glance like overcosted, uncommon Enlightened Guy. Giving it a respectable body could help.

Nice. Early game it's a cheapish small lifegain; late game it's potentially a large lifegain - but yur opponent always has a chance to respond.

Like it.

This seems like it could potentially be very strong, but maybe I'm misguided in that belief.

Well, I'd argue that it's a better card than Wellwisher, and that card is pretty damn strong. Gatherer lists it at a very healthy 4.560 stars, and, to make Wellwisher good, you need to keep an entire tribe on the the table. This card only requires you to have any number of creatures safely tucked in your graveyard.

Let's put it another way. How many 2 cost creatures do you know that must, at some point, be killed for you to win the game? One that had no inherent drawback, nor had hidden costs? I can't think of many.

Reminds me of Ondu Cleric.