If I give Mech Infantry transport capacity in the editor, will I still be able to airlift them and load them onto transports? And if I'm able to load them onto transports, will the units inside count against transport capacity?

I want to give my Mech Infantry a transport capacity of 1, and foot units only. After all, they're supposed to represent Bradleys and APCs. I think it would also help make Marines more useful, because with Mechs ferryign them to the front, they can keep up. Also, to bring along workers to build fortresses, and settlers to colonize after I've razed their cities.

My guess is not, in threads about getting copters to land on carriers it was found that it would not work unless their transport capacity was removed. The one thing you forget in your justification there is that those APC and Bradleys are already filled up with the infantry that makes up the mechanized infantry force. So they are not going to have room for the hitchhikers.