If your bottom bracket MT500 is going bad, then would suggest replacing it with an MT800 Hollowtech II. My MT500 went bad, crunchy and such only 20 miles after riding my mountain bike. You will not find the MT500 in the U.S. If it works, keep it and use it as long as you have a Hollotwech crankset. Otherwise, spend a bit more for a better BB with better seals. I had replaced mine with the MT800, which requires a different tool, but is a better BB. Long story as to why I didn't make the LBS replace via warranty.
Not really certain why you would want to exchange wheels or hubs unless your looking at just upgrading the entire wheelset for lighter better parts? You have the following hub: Formula DC-22, alloy, 6-bolt, Shimano 8/9/10 freehub, 135x5mm QR This can handle the 10 speeds and 11 speed cassettes. As long as you don't purchase a Shimano micro spline cassette, you should be able to use all the way up to 12 speeds.
I switched my mountain bike over to the AdventX from the Altus 9 speed groupset it had. Microshift has some really nice products now. Reviews that I compared the AdventX to, consistently stated this was a better derailleur system than Deore. But not quiet as nice or smooth as the SLX. My son's bike has the older SLX 10 speed. It's fun to compare, but both systems are in my opinion are on par with shifting capabilities. The SLX is more quiet and lighter feeling to shift. Where as the AdventX has a bit more loud of sound with the click, but feels really good when it shifts. I've gone up hills on this bike and had no grinding of any sorts when shifting like I did with my Sub Cross's with it's Alivio setup.
Only issue and a minor issue at that I have with my AdventX is the paint. Dirt, gravel, mud seems to stick to it much easier than the Shimano parts.