Note to self: finish this later.

I like him, though only the last ability is really white.

First ability makes sense as a W/G mullticolor (cf. Ephara, God of the Polis), though not mono-white. I thought about target crit gets +2/+2 and has lifelink and trample, but I really like the hexproof idea.

The first ability has appeared several times in mono-green. Ephara is white and blue, and so on her the ability is half of each color.
Anyway, I'm not saying that's a reason to change this. I just thought I would point it out.

Hm. Sorcery-speed hexproof seems dubious. There will be times it'll be useful, certainly; I can think of many occasions when I've thought "Such-and-such a tactical play would be fine, as long as they don't have a removal spell". But... [-2] on a planeswalker is quite a hefty cost for "preemptive hexproof". Compared with pure card advantage from the [+1]... I'd say the [+1] is a lot better than the [-2] at the moment. I don't think the middle ability wants to be positive-loyalty, but I'd prefer it at [-1] or possibly [0].

You make a very good point, Alex. I'm usually more concerned with combat tricks than instant-speed removal myself! I'm adding lifelink (as I originally wanted to) to it. I'm not clear if the +1 would require a cost of , but that's a development thing more than a design thing.