You keep them all right now, especially since McQuaid has proven he cannot stay healthy for a full season, the uncertainty of which kid will prove himself, Chara and Seids starting to show some signs of aging, etc etc. A d group that's 7 deep will help out a lot. You switch out someone for the extra when there's a slump, nagging injury, poor play, etc etc. In a perfect world, the games played would be something around this:
Chara: 80 games
Seids: 78 games
Boychuk: 75 games
Hamilton: 75 games
McQuaid: 60 games
Krug: 45 games
Bartkowski: 45 games
Vet Dman: 10 games
I like that a lot ,your missing 24 man games though, so Bart and Krug could get another dozen games each in they should be happy with something like that. Not sure what we need the Vet D for if he's only gonna play 10 games considering our cap issues. I'd give those games to Bart and Krug as well that will have them in the same amount of games as Quaider.