1. I do not get frequent crashes. A crash is pretty rare here.

2. I have never experienced this. If I select SEQ format it has alsawys saved as a .seq extension, and wav format as wav, etc. That said, there is a newer option added in this area in the last year; there is now a checkbox to set 'Default to SEQ format when saving a file'.
I don't understand how it could save a file without an extension. I've never seen that at all.

3.This was an issue for a couple versions. As you've noticed the Alt-Tab method works (as do others) as a workaround, but I feel like this was fixed over a year ago.

4. Sorry, I don't get this one either.
One thing I do know is doing this process creates a whole bunch of temp files in your Temp Audio directory.
Why? Because you can Undo it, and RB needs all those original chunks to revert to.
Not sure if that helps or provides a clue but thought I'd mention.

I just performed this action (tempo change) on a song with 9 RTs and it created 44 temp files. (Note that I had generated various sections on some tracks so I had lots of audio 'chunks' scattered around those 9 tracks).
If your Temp Audio directory is getting full or the drive is being overworked, maybe it lags too much (?)
I dunno. Just guessing, as I just don't see this result here.
Your Temp Audio directory can be set to any drive available, maybe that will help or eliminate some possibilities.

I'd also consider John's suggestion and try previous updates for 2017 as a test. Maybe a previous build will play nicer on your machine.



Make your sound your own!
.. I do not work here, but the benefits are still awesome