no 2 amps are exactally the same. With 2 theoretically 2 different amps on 2 subs in the same enclousure youll have problems. Just saying. You really just need 1 big amp. I doubt those amps are even strapable.
Tredmil wont be as efficient as outdoors. Stay away from junkfood and watch your calories is all you need to do. Eat 2k calories a day and you should watch the scale go down.
my alt was like that too, a plastic casing around the terminal. I just snapped it off with some pliers and sanded it down and the ring terminal fit fine.