To be honest, I would ditch the 3" BL, go down to a 1.25", grab some 5.5" springs, long arms will help the ride a ton.
If you go with long arms you can stretch out your wheel base a bit and get those rear tires more in the center of your wheel openings. This will stop the rubbing against the front of the rear fenders. Push it back 2-4"s.
Take the exhaust issue to an actual exhaust shop. They will figure out your routing as they are experts.
Just my $0.02
EDIT* forgot... you should run a fuel cell and get rid of that bulky tank.