If that was for me, I would have left in even the Prets and hoped for the best, but Dreaad made that rule, not me. I agree that Skavens are best left out, though, for clear reasons.
Summons, until I find something truly broken (and I still need to test a ton of stuff, from Demons to Bretonnian Counts) are in. And even then, I guess it's better to outlaw 'em strictly if needed.
Well most of the summons are broken tho, Bretonia has like 2 pearl ones REMOTE summons and all the chaos factions have sacred demon summons that are obviously under priced.