A deadline is, simply put, optimism in its most kick-ass form. It's a potent force that, when wielded with respect, will level any obstacle in its path. This is especially true when it comes to creative pursuits.
Rereading parts of your novel while writing is like doubling back at rerunning parts of a marathon midrace.
A novel rough draft is like bread dough; you need to beat the crap out of it for it to rise.