first of all my f150 200 with the Tittan V8 has a slightly rough idle also heat

also im wondering if i can use startying fluid to check the pvc and vacume lines for leeks?

yes,but that is not a safe way to do it,i know people do it,but you'll be spraying around when engine is running and hot and electrical stuff don't like starting fluid.could start a fire!if you have a small propane torch,you could crack the valve open,BUT DON'T LIGHT IT.when you move it around vacuum hoses and have a vacuum leak it will change the idle of the engine,with the propane going into the leak.listen for hissing noise all around vacuum lines.oh,you will here the one at the pcv valve,but you may have to cut back the foam insulation covering it.it is junk,and turns to mush,and splits,and flatten's out.it never did throw the check engine light on?