ghijohansson
Let us start with your second question.
You are creating/exporting a file from another computer. What program?
I lost you when you wrote
I film in PAL but the only alternative for saving for HD vimeo is in NTSC ....and..... But should I choose "save filter setting" or "save FTP setting"?
If you are exporting a Premiere Elements 12 PAL project to file for upload to Vimeo at the Vimeo web site, you have every opportunity to export with PAL settings.
But, for HD settings, typically NTSC and PAL do not have the same significance as they do for SD. But there is the consideration for regional frame rates.
Where are you seeing these "save filter setting" and "save FTP setting"? These appear to be Vimeo settings, not Premiere Elements.
I have not been there and done that ['knowingly". So, I present the link for informational purposes for you to make your decision on which of the apparently Vimeo options will work best for your situation.
As for your first question....
a. Replace Footage feature.
If you have poor and edited audio on the Timeline and it is tracing back to its thumbnail in Project Assets, if you right click its Project Assets thumbnail and select Replace Footage, you will replace one audio for the other, but the new audio with retain the edits of the one it is replacing. That is the major perk of Replace Footage which may not be to your advantage.
b. Other.
Import the new and improved audio into the project with Add Media/Files and Folders, delete the poor audio, and drag the new and improved audio in to replace.
Please review.
Thank you.
ATR