Life Leech: Druid tornado doesn't benefit from life leech. I would guess this is defined as a spell (rather than attack) and thus doesn't benefit?

Mana Leech: I'm convinced mana leech doesn't work... both my cleric and shaman do massive physical attacks with a decent amount of leech and even on normal I'm not seeing a return on mana beyond the normal regen.

Yep. I broke mana leech. Fixed next update. Tornado is a physical attack, but a physical one. It doesn't leech for the same reasons earthquake doesn't. Magical physical! It can be a thing!

Ah, when I saw you didn't make tornado leech I came to check this. You're probably right to leave it as is, but you were considering it!

I think down the road spells will be changed to leech as well for balance purposes anyway but that's just me.

If you're a caster, I'd recommend loading up on regen instead.