should i take the factory plastic bedrails off to put on a camper shell? i even have a plastic bedrail on my tailgate. should all this come off to get a good clamp on my bed?

 

It would be ok to leave them on. It'll keep your paint from getting scratch marks during the installation.

 

You should not have to remove the plastic trim.
Here is a different type of soft camper shell from Ford.
In the video you can see the trim has not been removed.
I would think it is the same for other camper shells.
http://www.softopper.com/Videos.aspx

 

Don't. No need to helps protect your bed as well.