I was just thinking Beethoven influence with the coda cause you know contrast of chords and octaves against melody and countermelody, contrast of rhythm, contrast of dynamics with the subito fortissimo.
I mean, the original theme had a pickup, and the first note in the measure afterwards feels like the downbeat, so I didn't really see much of a choice here, I felt the pickup was necessary, cause it's part of the theme and all.
Honestly, I wasn't even checking for parallel octaves. I only tend to do that when Baroque style counterpoint is my goal, like in a canon or in a Baroque style dance piece, or a fugue. In variations pieces and such, I tend not to check laboriously for parallel octaves cause I figure that
If I'm going to have a parallel perfect interval anyways I prefer the sound of parallel octaves over parallel fifths
It's not really going to be noticed in a non-Baroque style piece
I mean, the reason I did that was because the original melody ends on the third and here I was moving the melody into the bass for Var. III and IV. But maybe you're right.
I do use slurs to indicate legato in strings and woodwinds. I've had a tendency to not do that for piano though, cause as a pianist, I myself play legato by default unless there's indications that it should be otherwise(staccato, repeated notes, slur over staccato to mean portato aka mezzo-staccato, performance practice for the piece(especially relevant in Bach), leaps that obviously can't be done legato(lots of that in Romantic Era repertoire), octave melodic statements(very common for me to see in Beethoven)). I'll play a Bach Allemande legato, just as I would a Mozart sonata or a Beethoven bagatelle or a Schubert impromptu, regardless of whether I see slurring or not and for as long as I don't see contrary indications(which I don't see slurring at all in Bach usually, minimal in Mozart left hand parts, Alberti Bass or otherwise, more so in Schubert, but plenty of non-slurred legato as well). When I do use slurs in piano parts, it's usually the long phrasing type, not the shorter legato type.