I've narrowed down my selection of pieces I want to learn in the coming year and was wondering if I could have any input or comments on the pieces I have chosen such as difficulty or graded standard, your opinions on the pieces etc.

I will only learn one of the bach, beethoven or mozart pieces so I have to choose just one of the composers and just one of their pieces. I will also learn one of the chopin or grieg pieces.

BACH

Prelude or Gigue from English Suite no. 3 in g minor, BWV 808
Allemande from French Suite no. 6 in E major, BWV 817
G minor sinfonia, BWV 797 (From inventions and sinfonias)
Prelude and Fugue no. 2 in c minor, BWV 847 from book 1 of WTC

BEETHOVEN

Sonata in c minor op. 10, no. 1, movement 1 or 3
Sonata in c minor op. 13, movement 3 (pathetique sonata)

MOZART

Fantasia in d minor, K. 397
Sonata in f major K. 332, movement 1

CHOPIN

Etude in e flat minor, op. 10, no. 6
Etude in a flat major, op. 25, no. 1
Either no. 1 or no. 2 of the etudes from Trois Nouvelles Etudes
Prelude in d flat major, op. 28, no. 15 (raindrop prelude)

GRIEG

Lyric piece, 'to the spring' op. 43.

I will be learning them as part of my assessment for my music class. All comments are much appreciated.

The Beethoven sonate pathetique is such a wonderful piece!!! But it has a huge technical contrast with Mozart fantasia in D Minor. Are you looking for pieces that are your level, or just nice pieces? The Mozart is easier than the others you have listed, but there is a lot of music to bring out in that piece!

The 2nd movement of Sonata Pathetique is so nice! Also the whole of the other C minor 1 - it is a bit tricky to begin but is loads of fun! I think movement 1 is around grade 6 ish, possibly 7, but I might be wrong!

I'd say Op10 No 1 1st movement is certainly Grade 7, as is the last movement, depending on how 'presto' you play it.
BACHwise, I much prefer Book 2, the C minor from that is OK. The Mozart F major K332 on your list is set for Grade 8 this year , but its nothing like that standard in my opinion, easier than the Beethoven Op10 No 1 above