I'll throw my 2 cents in here why not
1) Playing files that are above your level is good, but make sure you're actually trying to hit the patterns and not just mashing. otherwise, you might as well just jump straight to 110 if you want to mash.
2) Mashing is not bad though, it is basically exercise for this game in my opinion. If you can't FC a file, you definitely cannot AAA it
Mashing builds tappy speed
3) So in conclusion make sure you play files that you can play well, as well as files that are hard, but not so hard that you can no longer read any of it. But hey throw some mashy files in there from time to time to get the blood moving.]
4)Improvement takes a long time. You're probably just plateau'ing, something you better get used to. Given your 11 im sure you'll be improving soon but, thats pretty standard on this game. #skillboosts