These don't sound like unusual problems for that kind of mileage. But it does sound like what you really want is a reason to buy a new bike, and you're just seeking validation of that choice. If you want a new bike - do it - and other people's opinions be damned. But the wheels on your BigB were machine-built (which are always a bit less than optimal), and I think you could have them re-built by hand using good quality spokes and be just fine.