Apologies if this has been covered already, but is your film fresh/known good? I've just developed some rolls of 120 format that are *very* expired and the frames towards the outside of the roll as it has sat unexposed all these years are dark/fogged to the point of being impossible to print.
Also, I have a Stylus Epic (same as Mju 2) and the film advance is fairly loud. Not as loud as a motor drive SLR but I couldn't take a shot on the street without someone nearby hearing it. Manual advance, leaf-shutter rangefinder or scale focus viewfinder cam might be your best bet for the street work. I have an Olympus 35 EC 2 that winds on like a disposable/re-usable plastic camera.