Eldritch Life- cool feat mechanic! Are [Story] feats your own homebrew?

Assuming a 9th-level wizard with Int 19 (Int mod =+4), you'll have 4/5/5/4/3/1 spells per day, including spells from high Int. Assuming you devote yourself to just sitting home and converting your spells into healing, that's:

4 0th-level spells: (0x2.5+4)x4 = 16
5 1st-level spells: (1x2.5 +4)x5 = 32.5
5 2nd-level spells (2x2.5 +4)x5 = 45
4 3rd-level spells: (3x2.5 +4)x4 = 46
3 4th-level spell: (4x2.5 +4)x3 = 42
1 5th-level spell: (5x2.5 +4)x1 = 16.5

Total: 198 hp/day gained from converting spells. So after ~5 days you'll have healed enough to gain the template, something to keep in mind when you assign benefits to the template (which is already pretty good, all the benefits of being a construct but none of the drawbacks; I'd be looking at LA +2 or so).

I do like what you've written for the template so far, Arcane Constitution is powerful but also has a very flavourful drawback (using up your spell energy literally drains your life force, very nifty).