4) More fan involvement. MSTF was always a blast. More like that! Block out a room and fill it with fan-run workshops and panels, with a low barrier to entry. Put a disclaimer in front of necessary. It's a pretty standard practice for conventions, and helps the attendees feel more like the con is for them.
Being a licensed convention really limited areas like this. Too many people needing to screen and sign off on such things to make sure they still fit whatever vision the brand had for itself at the time. THey would need to have a solid pitch and content that could be vetted beforehand.