You know what, I'm having a hard time concentrating. Next time use small paragraphs between each point or question.
As far as backfiring, make sure your plug wires are on correctly and firing order is correct.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black