I've seen a few videos of you, you're doing a great job! It's already a couple years since you posted this one so I bet you're just getting even better now!
In the sort of "theme" in the first section, I really like that you are using the thumb on the bass notes even up to the third string. That is important for emphasizing those in the right way and I know a lot of modern players discourage using the thumb on anything but the fourth through sixth strings.
To make it even better, you might try to extend your phrases... So, in your head, instead of feeling one-two-three, one-two-three and so on for every measure, try taking every two measures and counting the beats to six and let that whole thing be a group of notes played as smoothly as possible. Beat 4 in our pair of measures should be somewhat strong, just not as much as the first one. Then come in a little stronger on the next downbeat.
This is an idea a teacher gave me on a different waltz I was playing but I think it could apply here. Going to have to try it myself!