7 footers would be okay, as long as their pockets are tighter. Sure, the long shots on a 9 are now easy straights on a 7, but that's not gonna make things a crapload easier for anyone other than bangers who will mess up on position play along the way and lose anyway. The biggest change is ball speed imo, and cushions. From what I've seen, 7 foot tables usually dont have large cushions and that usually messes up pros who depend on multiple cushion banks and kicks.
The only thing I can't stand are those bar boxes with gigantic ass pockets, the kind where if a ball gets close to the pocket, it drops in. An example would be the Valley 7 footer bar tables, it takes very little skill to pot balls in rapid succession on those, compared to on a 9 foot brunswick with fickle pockets. And I'm speaking from experience. I started out on 9 footers, and finally one day I come across a Valley 7' at a bar. Me and a friend start playing on it (free pool that day), and I couldn't believe how easy it was to make balls. However, my banking was completely off because the rails felt stiff and my speed was messed up due to the scratchy cloth.