Don't worry about the Olympia making a bit of noise. My Super J still does it even after I put new bearings in it. I'd imagine the fans are a bit dirty and have put the motor off balance slightly. If it makes strange noises when at full speed or squeals at any time, then I might get worried.
The rumble seems to be a Lux characteristic. Not part of the design, and not really a good thing, but it seems like most have it by now, and run with it just fine.
