Thanks for uploading the project. I had to dig into it a little, but it turns out that there is a bug in the TrackedDolly behaviour when there is no Aim component and the Camera Up mode is Default. That’s where the weird rotation is coming from. Thanks for bringing this up, we will fix it right away.
For now, a simple workaround is to put DoNothing in the vcam’s Body section, and add a CinemachineDollyCart behaviour to the vcam, set the path there, and animate that component’s position, like this:
That will make the vcam travel along the path.
Let me address some of the other issues you mention.
If you have a Cinemachine track with an active CM clip on it, that completely overrides the priority system. You should not have to animate the priorities, ever, so long as there is always an active CM clip on the track. If you leave a “hole” as you do in the project you posted, then the priority system becomes relevant within that hole. It’s best to always have a clip, so that timeline has full control of the camera, making the priority system irrelevant.
This is the “hole”, where there is no CM clip, and the priority system takes over:
Recorder: I am not a recorder expert, so can’t really advise about that. Perhaps someone else on this forum knows and can answer. It seems to me that to include the canvases you have to record the game view. I don’t know why the resolution is wrong, but surely there is a way to get it right or it’s effectively useless. Is it possible that your game view needs to be the correct size on your display when recording?
Perhaps you can ask on the recorder forum: Unity Engine - Unity Discussions
Timeline: You bring up several issues, and I suggest that you post them on the Timeline forum. Here we focus on Cinemachine-specific things. Timeline forum is here: Unity Engine - Unity Discussions