Tell that nissan dealership to get bent and fix the problem. If you bought it new, it should be under warranty anyways. Don't let them d!ck you around.
As for your mouldings, use a heatgun, a putty knife that is wrapped in tape and have some goo gone or lighter fluid ready for after wards.
Start on edge of moulding by applying low to medium heat to area but DO NOT leave heat gun on direct area, use the heatgun like a blow dryer. after the area is warm to the touch, use putty knife to pry moulding from car. Work slowly and be patient. You don't want to ruin your paint. And be easy with the putty knife. Like i said, wrap the edge in masking tape so the edges are blunt and will not cut into the clear coat/paint.
It will take some time but you should be able to take it all off in an afternoon. After they are taken off then go back and look for any residue that was left from the adhesive. Us ethe goo gone or lighter fluid on a cloth to remove the residue. Then wash your car after it is all done.
Also if you need anymore info on your 2.0 myself and a bunch of other guys frequent a forum called
http://www.B16sentra.com you will find way more knowledgeable info there then you will here. There are a lot of us B16 owners there
. Looking good 
