That is very strange. So basically you're saying Firestone tech says on the right front tire, the top of the tire is sticking AWAY from the body? (+1 degrees camber) Unless there is something screwy or has happened on that part of the car, that tire's top should lean INTO the car like the other 3, because that's how the suspension geometry is on pretty much any independent suspension car. There must either be a bent control arm, OR something peculiar on the Altima coupe that causes this (but I have never read anyone else state this so....).
How much did you drop the car? Might just be that you have to go the camber bolt route and get it right.
The rest of them at -1 degrees, is that the max it could go or did you want a slight cambered look? I take it that is the max due to the extent of the drop. I'd have to see it to understand what's rubbing because of the off camber on one tire, but I'm definitely no expert.
Edit: Also, is there any reason you are hesitating taking it to Don Davis or other Nissan dealer? I typically paid $89 for alignment and they always got it on point 1-2 tries (steering wise). Even with your mods I think they could at least let you know if it's at the limit or if there is something really messed up on that one wheel. Just a thought.