After re-reading this thread and thinking a bit about it here is a loose proposal of what I think Mimi-Mac could be. This is one man's idea that is open to being discussed and torn apart at will, by anybody...
1) Mini-Mac shall be three classes. We'll call then A, B, and C for the time being. "C" is the lowest/easiest class and "A" is the highest most difficult.
2) ANY size plane may be flown with the upper limit being 30 cc. (wing span & weight open for debate). Rule #3 may solve this issue???
3) The airframe shall be a copy of an aerobatic full scale of past or present. (deviations from scale open for debate).
4) Sequences will be derived from the Aresti catalog similar to IMAC. (You could just use the current IMAC schedule).
5) C class will fly a non turnaround sequence. (Give the new guy a chance to gather his wits between maneuvers). B & A class will be flown like IMAC.
6) You can move up a class at will, but must make a request to move back down.
7) Simple scoring system 1 - 10. (I see a lot of debate here
8) Registered pilots will be required judge in a class not their own. If there are not enough registered pilots to make up a panel of judges for each class, pilots can judge their own class. (Be fair as your turn in the air will be coming up) This could be an issue but I think could work out OK.
I realize this leaves a lot of holes but it is just a list to spur some debate
Keeping the rules a simple as possible may spur some club level activity. Make the event almost a fun fly level of competition (at least in the C class) to encourage pilots to attend and fly. Low entry fees, simple scoring etc. If you can get some clubs involved, it might just grow in a particular region and open up the door for pilots to move up to IMAC.... or just be satisfied where they are at.
OK, my flame suit is on, so fire away