That's a clever idea, but the interface might be a bit awkward. For rotations, it'd probably just be enough to add a "Treat each item separately" checkbox in the manual transformation dialog (Ctrl+M).
When you select multiple groups, would it rotate each group, or each individual element in the group? Perhaps the "ignore groups" toggle could let you change the behaviour. A macro system could also help with performing the same operation on multiple items, though that's a different thing entirely...
In the end I want to have a scripting console of some sort, so you could type something like this in and it'll do it automatically:
selection.Each(x -> x.Rotate(45))
That makes it really hard to keep an undo stack that won't chew up all the RAM, though.