Hello Henry!!!
There isn't much to be said, since most of what I thought about was already mentioned by other composers. They provided detailed feedback, so I'll just share my thoughts real quick 😄. I listened to both versions, the first one and the final product. I loved the A major one, even though I am a E flat and A flat lover hahaha. A grandiose waltz or any grandiose piece, in my opinion, should be done in the key of open strings. This will give much more power to the violin's sound and projection.
First, the introduction is very, very well done. The grandiose feeling is perfectly portrayed. Main themes do not need to be extremely complex. It is a waltz, and the simplicity, yet beautiful melody, makes it a perfect main theme.
The first version had the violin playing a ton of chords. The violin is primarily a melodic instrument, and should primarily play a single line most of the time. I recommend using chords sparingly and focusing on the violin's melodic capabilities. In the new version, this was fixed pretty nicely, which made me very happy.
Make sure to repeat sections, like previously mentioned by others. Not only does it give structure to the piece, but satisfaction to the listener as well, specially in a waltz where many, many sections have repeats. These sections are usually simple in structure, so the listener enjoys both the first and second, possibly even third repeat.
About the difficulty and playability. Some specific passages in the piano part are difficult to play due to their fast tempo or close spacing of notes. Consider the playability of certain sections and make adjustments if necessary.
Overall, a very, very nice piece. The introduction and the main theme got me engaged in no time, since its what I expect from a waltz, specially a "Grande Valse". Excellent job! 😄