scrapes

Well i just lowered my car and its about an inch above the tire all around but i scrape just driving on straight road if the road is uneven... I have the kiddsracing header which makes the exhaust hang way low... I was wondering what else is out there that would make the same power... Any...

driver door sags down so when i close the door it scrapes on the lower door frame. How do i somehow lift the door? and also u know how there is "positions" on doors. like they somewhat lock midway so they dont just close. well my passanger door closes nice and has that lock, but the driver door...

On my hood it looks like someone took a piece of steel wool and went back and forth. The scraped are in like a checker board style...with intersecting perpendicular lines. How do I remove this or buff this out. Do any of those produts that claim to remove scrathes really work?