Yes you can! It is the same bar/chain combo on the MS211.
Bar part number: 30050004813
Chain part number: 63PM55E

Your running a .043 bar and chain, u can go with a .050 bar and chain.. wouldnt recommend though because you power to bar and chain are mediocre you put on larger, it will require more power to run the loop and there for cut slower

Sure can though dealers are instructed to tell you it can’t be done.
Some say it will void the warranty but if you spend the extra on Stihl parts you can argue the case easily provided you don’t go overboard.
Contrary to a couple of comments I’ve seen it’ll improve your saw a great deal though you’ll have to be mindful of bearing down on it, it’s just a baby after all, just take a little time & get used to its new & greatly improved character, you won’t be sorry.
See my review for details.

Make sure you have the correct size file for the chain and are sharpening at the proper angle. Sharpen from inside to outside of tooth using a forward motion only. I initially had the wrong size file and it wouldn't sharpen the chain at all.

Hi Rick,the problem is the rakers, those bumpy things in front of the teeth. Get a small flat file and give each one a couple strokes, file in the same direction as if sharpening. Try cutting again, there should be chips not dust. Repeat this process, until chips are achieved. The more you file, the more the chain digs in. You don't need to do this every time you sharpen your chain, only when you notice dust or the problem you have now. Good luck and may you spit chips.

Stihl makes a offset file that has a flat file and 2 round files in the tool. Ie as you sharpen the tooth the flat file also takes the rake down to proper height. If rakes are not correct, sharp cutters will not be able to penetrate wood