the novas seem pretty easy to power everything else, so change the 4 QTs to 4 time towers and maybe only 3 towers would be sufficient imho
Nope. Try that deck and you'll figure out why all those QTs are necessary and why more towers would totally a waste.
You're right, time quanta is fine with mark, but I had problems with gravity quanta especially if the opponent was spamming a lot more creatures
So I would prefer changing 2 of the QTs to gravity towers, as drawing one at turn 4 is perfect and sets you up nicely for the rest of the game