I'm not sure I've got the first two questions, my reply would be NO to both cause I think the sequence is part of the preset. Anyway other guys could tell you better than me...
About the external input, which sequencer do you use? Unfortunately for what I know the thing is not so usable inside Logic, while you should have no problems with Cubase/Nuendo. Don't know about other hosts...
Anyway, you should use the external input control and switch which are in the center of the MiniMg... you're right, the manual is not clear about this kind of use as efx...
maybe someone at Arturia could put up a little tutorial on this thing :roll: