If the tires don't wear funny, it's only astetic.. so up to you..
If the tires are wearing funny because something is off, then it's totally within reason to fix whatever might be wrong...
wont make any difference
these cars are 'off' by that much when they are properly corner balanced anyway
Having it put on corner scales will tell a tale I'm sure... It'll cost ya, but it'll be worth it..
That's if somethings not bent/broken as suggested above...