I'm new to Soraka and a fairly new player in general. I had previously been buying the shop-recommended items, but with Warmog's for the health regen. I think your guide philosophy is bang on - there is no point in having loads of health because healing costs 10% max HP regardless. It's best to have health regen, in which case spell vamp makes sense. I'm keen to try this build tonight.

It also solves the problem I was having with Soraka late game, where if you're the sole survivor despite your best healing efforts, you cannot do enough damage to stop even a one-man base rush.

Regarding the spell vamp, do you recommend attacking minions in (bottom) lane? Or do you not get the spell vamp items early enough, so that it's group-fights by the time you get spell vamp?

Also, how do you feel about getting q before w, and with levelling q and w equally instead of prioritising w?