He can if he hurts Cain early and stops the TD without gassing. I can't really see JDS dominating in a decision victory. It would probably be a decision where he gets a couple rounds by hurting Cain or outstriking him while avoiding the TD, but Cain probably will take some rounds via TD/pressure etc.
Much more likely that JDS wins via KO instead of decision.
It was always the consensus that Cain would have the advantage the longer the fight went.
Nope, because that would mean he would be tagging Cain and winning the fight on the feet. Cain would be knocked out before then.