I was thinking about this the other night. Implementing this would be pretty pluasable.
Here's my idea:
Fox example, when you Air Dodge, there is a 30 frame window (approximately), and within those frames, there are invincibility frames by which you can't be damaged. Now, what if the amount of frames for the Air Grab was the same as the Air Dodge? It would possibly work, and it can be balanced.
When you grab an opponent, you remain in the air for a breif period just like the Air Dodge, but the amount of time you have to throw has the same amount of time as the Air Dodge. So if you don't hit a direction within the 30 frame window, your opponent will break free.
The throw velocity will vary based on damage(Melee Terms, assuming that Brawls throws increase in strength). So don't expect to get an easy kill.
I'm thinking whether or not that the Air Grab should count as a 3rd jump.
Any ideas?