I don't believe the files are encrypted.  The file names are randomized and the file has to be extracted from the 7-zip container.  If it were encrypted, you would need a password.

The file names are randomized because Peeje was deleting a lot of them as they arrived for a while, as have other services.  With random file names, people who want to know what's on a server have to take extra steps to download and find out, rather than a simple directory listing.  Therefore it's harder to identify links to be deleted.

This is a bother for us, but less of a bother than dead links.

I could enable the scrambling for other hosts, it just depends on whether there's actually any benefit in doing so...

I think you have a misconception here. I highly doubt that anyone is viewing all the files being uploaded, rather they have a program that will flag any suspicious file. if a file was flagged then I imagine that an employee would then investigate the cause.
Or possibly they would do nothing until the specific file has been reported or has an DMCA take-down request.
In rare situations (such as rapidshare last year) they would remove files within hours by monitoring the number of downloads per file and if an file matched an known illegal file, that would get removed too (by comparing the binaries of the two, so renaming and the like didn't effect the outcome).
In terms of complexity "looking" at file names to flag illegal content is easier (and faster) then comparing the binaries of an registered illegal file and an suspicious file.

However each site functions differently, so it is hard to tell how the removal process works, renaming / archiving files might work on few, but it wont on all.

That is how I believe removal process work on file sharing hosts.

I think if someone's looking at your files in the first place, there isn't too much that you can hide (save for going into encryption or stenographic measures, though I doubt the latter could be done well).
Simply viewing the video gives away what it is.
The idea is to not make them look at the file in the first place.

Peejeshare was never good or popular ,neither was sendpace.If you read the Admins comments on here then you will know peeje is unreliable and a lot of the uploads fail or are deleted quickly ,and the site is not very good.Also premium sites like ,up.to,nl,rg,etc are all fine and work great if you are not a  leecher who expects free file hosting like you.