B-25's off of CV's isn't going to happen.
It was a one off attack with seriously modified bombers. I believe they stripped all of the guns and armour out to make her light enough to take off from the deck.
Saying that, I would quite like to see some different carriers. Maybe, as you mention have a large or small CV, the smaller ones being equivalent to the Escort Carriers in the Battle of the Atlantic. Have only Hurri's, A6M's, F4F's and Seafires available (Maybe leave off the last one if it will upset balance) but as a trade off, make it much quicker and more maneuverable.
This wil mean you have a choice between slow and good choice, or fast and limited choice. Escort carriers would primarily be used as base defence, if you see a base trying to be sneaked on the coast, send as ECV down to help the defence.
Just an idea.
+1 for different CV's
-1 for B-25's off of CV's