Re wearing out, yes the chain drive does wear out quicker, but they're so cheap it's not worth swapping chains out - I.e., one chain per chain drive (front ring, rear sprockets and chain) change which can be as much as 10,000 miles. So it kinda balances out, the rims wear out quickly for me as I'm heavy and it's hilly where I live, but they're only ~£20 and take an hour to change.
The M+ tyres do wear quickly, I tend to only get 2-3000 miles on the rear. The OEM tyres do last a lot longer IME.
The rear hinge can wear wear out quickly or last ages, my 1st brommie's hinge wore out in less than 4000 miles but my others haven't needed changing past that..go figure.
Maintenance wise...2 speed is a PITA and doesn't seem to like the northern grit when it rains torrentially. The 2 trigger system for 2/6 speed works but gets on my nerves especially when the 2 speed packs up - which means you end up with a REALLY wide 3 speed.
The best combo I've ever had for the least amount of maintenance was the 3 speed BSR and Schlumpf mountain drive. I never touched it for thousand of miles....in fact I'm converting one of my existing B's to this again (I sold my last one as I thought I'd not need the fold again).