Questions about OSX Mavericks

Hi all. I'm currently downloading OSX Mavericks to my 15'' late 2011 model MacBook Pro that currently runs OSX Lion. I have a few questions about how the upgrading works as I have read good and bad things about this OSX upgrade.

1. I have a time machine drive that backups for my Lion system. How does it work once I have Mavericks installed? How do I get all my files back on the new interface if I do a 'clean install'?

2. I have Pro Tools 10. Will it run with Mavericks installed?

3. I have Office for Mac 2011, will it run on this new Operating System?

4. If something goes wrong, can I revert back to Lion?

5. How can I recover my emails?

I may have more questions later as these are the only ones I have at the moment.