1) You should have a fuse on the positive lead coming from the front battery to the rear or second battery and also a fuse before your amp. 2) Yes you can, but this adapter will probably have to be custom made. You can get a thin piece of metal, bend it and drill it to fit on your post, then tap it so you can screw the ring terminals onto it. I saw something similar on a build log somewhere on this website. If I have to do it when I install my battery in May, I'll do a log of it for you! 3) Yes, you should do front battery (+) to rear battery (+) and front battery (-) to rear battery (-). Hope that helps! Let me know if you have any more questions. EDIT: Spelling