The short answer is it depends exactly on how are going to do things. A cheap mic and preamp will sound terrible, but a decent mic, good preamp and good guitar acoustics might make it sound awesome. Here are a few of my thoughts after reading your post:
1 - It might not sound anything like an acoustic in terms of tone or volume, especially if you don't have any kind of soundhole. This is because the enclosed air mass inside the body acts like a spring, so the body's pieces can't expand or contract very much, resulting in very little difference from a typical solid body sound. If you put in a sound hole, that may or may not be different, depending on body design.
2 - If there isn't much acoustic excitation, a mic is a bad idea, because the signal to noise ratio will be so low that you will be amplifying all the noise and your signal could sound like crap. However, if there is a good sound, and the mic and preamp are of high quality, you just might be able to get it sounding decent. I don't see how that is aesthetically more desirable, however, as the mics would look like strange little dots.
3 - This has more to do with the body itself, but if you are going to use plexiglass or acrylic, why not try making a mold and casting it using waterclear epoxy resin? Total materials cost wouldn't be much more than using good quality woods if you shop around and don't waste a ton by practicing on full size pieces. That way, it would be clear, you wouldn't have the (what I would think) mismatched aesthetic of the wood and plexiglass body. Of course, that is just my two cents there.
4 - Another note on the electronics, I would still do pickups, but you could combine them with a piezo bridge signal or a contact mic on the body if there is enough excitation. Then you could blend the signals together with a blend pot or something and have a huge range of sounds as opposed to a single gimmick. I have a bass with a piezo bridge and two pickups with blend pots. Having the continuously variable combination of the three different signals gives me the ability to get a whole world of sounds. Again, my two cents there.
Hope those thoughts help.