If I had to guess looking at just the songs you listed, I would say you're moving along at a pretty fast pace for only 2 years of piano playing!! However, I'd have to hear it/see a video to be sure, because piano playing is much more than just learning notes-- can you play them smoothly, fluently, with expression, with dynamics, etc? That's what matters in music. But assuming you are incorporating all of the expressionistic aspects, I think you can go very very far in this musical endeavor if you keep practicing! You have a GREAT start with that repertoire already under your belt!! Keep up the good work!
I think you will do fine working on Mozart's Sonata K.545. If you have worked on scales already, that will help with this song. Just make sure you are using correct fingering when you start learning this song and it will pay off in the end!
As far as grades/levels for piano, none of my teachers ever used grades and I am not very familiar with any sort of free assessment for piano to determine a grade or level, but you might be able to find more info on this site if it is really important for you to be identified with a grade:
http://www.abrsm.org/en/home
