Greetings blockend, welcome aboard. Your first sentence says it all for the most of us. Sub-min is of itself, appealing. We all own and use 35mm , MF and some larger too, I'll bet. This household has several high end digitals too, and they satisfy some of your questions.
I think, personally, it's the challenge.
After all, one can take the corner of a 24x36mm frame and enlarge it, but the perspective would be like a tele lens, just for starters. Then the lenses of bigger cameras don't have the precision - as well shown on a thread over on Submini-L by Joe McLoin. He took a Minox thru 16mm and on up to 4x5" and arranged the shooting distance so that the subject of interest (his garden shed) was the same area on all the negatives from smallest to largest. All on the same fine grain film and all with the same developer. The Minox and the Minolta won hands down for detail and acutance. He did it just for the 'denyers'
that is those who, like yourself I suspect, can't quite see the point of the struggle (and it is, often) to work with the equipment. It can be so easy to go 35mm and bigger at the same or even less cost. That leaves you with one factor to forget and concentrate on the image.
But if you go around the net or cruise Flickr and sample what is done with the like of the cameras here you will be sorely tempted, I think, to try your hand.
Panoramas from a conventional film size are an extension , in a way, of subminiature. Have a Nikon that switches as you will from normal to pano but getting the darn things printed correctly has been my biggest problem. They are all in colour and I usually shoot B&W for sub-min so's I can load and develop myself. Colour I leave to the lab.
Hope this answers some of your good points raised. We all ask ourselves the same questions I'll bet when things don't go quite according to plan!
Cheers
Murray