I wait till late winter / early spring to prune. I remove any spent blooms in the fall after they brown, otherwise the weight of the snow can cause branches to break.

Its going to drop all the leaves in the fall, if you are worried about winds, I would stake it.

in in terms of the right branch I’d leave it for now and see what happens next season but that’s entirely up to you.

If you stake it for winter, leave it a bit loose, not tight, and it should be removed next year so it develops the root strength to stand without support. I don’t see this as an ongoing issue since my paniculatas are fine unstaked in an exposed spot in a windy river valley. I would likely remove the right branch.

Looks good, Sara. I too would cut the botoom right branch for aesthethic reasons. Pruning will be easier when the leaes dry out and fall... So you can see better what needs cutting.