I used to run a 33 card rainbow after using Alaska's deck and before using Jmizzle's (or a tweaked Jmizzle's). It had 10 towers and didn't use S'Novas. But I've started to use it again and I've decided I like the 7 tower and supernova idea. So here's my version of your deck.
Changes:
-Added Eternity - not decking out and reverse timing bothersome growth creatures.
-Added Fire Storm - to me, fire storm is one of the best cards in a rainbow deck. So I added another.
-Took out Twin Universe - in my opinion, the TU only helps the win rate against Hermes and Graviton in some cases. Against other gods that don't really have something worth copying, I really feel that you don't need more than one copy of the same creature on the board. Hence I would almost always rather have a fallen druid in my hand rather than a TU, or an otyugh or a quantum tower or a sundial rather than a TU.
So far, it's about a 60-70% win, but maybe I've just been getting lucky. I've lost against Hermes and Obliterator.