I use the brown permatex to seal it....Used to apply the Blue RTV ..

As for the rocking...take it off and file it down. It can't be that hard. Go in single motion in one direction. I had to file my one cast iron HP manifold and it took me 10 hours over 2 days to do so. Don't double up the gaskets because the gaskets will probably end up blowing out while you are on the road and then you will wish you had done it the right way. If you gotta get the car somewhere fast, then yeah...double up...but don't leave it accident prone.