I agree we'd have no trouble for a some of the bigger games, and to be honest, it seems a very British thing to worry about empty seats for 'lesser' games. Loads of events outside of English football operate very successfully without needing to be 95%+ capacity... e.g. Concerts, trade shows etc.
Sadly, with our media, and public perception, if you build a stadium that's 'over capacity' for too many events, it's portrayed as a failure, which I'm sure the owners are conscious of.
I'd only want to give away more allocation to away fans if we had to (but you're right, it would heighten the atmosphere). I'd still rather City fans got the tickets though!
Not sure on the 10 games a season...
United - definitely
Chelsea - definitely (if they continue to be rivals)
Arsenal - definitely (if they continue to be rivals)
After that, I'm not sure Everton / Spurs / Villa fixtures etc are all that compelling any more (for City fans)? But there's always going to be a cup games, CL nights and some 'crucial' fixtures against random opposition that will be highly attractive I guess.