I'm looking at a new set of rims for my 07 FX4. Right now I'm running the factory FX4 18" rims with 35/12.50-18's and a 2" level kit. They only rub at full lock and sit about flush with the fenders. The rims I'm looking at are 18x9 with 4.52" backspace and a -12mm offset. Will these rims make the tires stick out from the fenders or cause worse rubbing. Also would I have issues with the pressure sensor if my factory rims have it. I'm not sure if it does or not but I dont really want to spend another $300 for replacements if I dont need to.

 

That wheel will stick out 2.5 inches farther than your oem wheels and they will cause some major rubbing. You will need to add more lift or find an 8 inch wide wheel with 5.5 inches of bs.
Your options with your TPMS is to either live with the dash light or buy new mounting bands and have the sensors moved from your oem wheels to the new ones. You can buy them from Tire Rack for less than at the dealer.