Ah - without looking at the possibilities for SQ again, I couldn't say.
I will say I was considering something similar (reading an interview where this was discussed, wildhsape didn't get SQs because the type of SQs increased with the revision since more creatures classify as animals and they didn't want to make some long list as to what would and wouldn't be allowed). Having read that, I was thinking I would just allow SQs related to mobility (sprint, etc.) and senses (sight, scent, hearing related type things)... again, still have to finish looking over the types of SQs that could be allowed before I come up with my catagories.
But back to your own suggestion, it does seem reasonable. You may want to glance at the potential SQs first, though, to make sure there isn't something grossly unreasonable. Of course, giving up SAs is significant in itself for some creatures.