Did you even read the Secunia links you posted? Both unpatched vulnerabilities require usage of Apache's mod_ftp module, which I've honestly never even seen used as most hosts and general servers use external (and hardened) FTP software like ProFTPd:

And the second (first in order on the site) unpatched vulnerability deals strictly with a mod_ftp input validation issue. Again, I rarely even see mod_ftp even used as opposed to an entirely seperate FTP server daemon but disabling the faulty module is simple enough in environments requiring absolute security.

And input validation issues are usually patched fairly quickly anyways, I mean come on, this is 2009 and there are too many developers for the project that wouldn't let this sort of thing continue for this amount of time. Not to mention the fact that these unpatched vulnerabilities are nothing compared to the olde IIS Webdav exploit of a few years ago - too bad there wasn't a community aware of it sooner other than the underground black hats already using it to their advantage by the time it was brought to the attention of MS.

Yeah I get those at the bottom of websites all the time, usually because I'm the Xth visitor etc. For some reason, the prize is always a bunch of forms to fill out promising more prizes. (this is a joke, by the way)

This is probably an effort to keep inode count down, so as not to overtax the filesystem. Having a million 1KB files can be more expensive than having a single 1TB file, depending on the FS, which they apparently worked out in order to impose this limit. They could also be trying to keep down extraneous file hosting (hurting their business as a host) in the same manner that you can't share a Comcast business Internet connection amongst clients.

That'd be my guess, in addition to just plain common sense: why/how on earth would you need 50,000+ files anyways? Something a database couldn't satisfy?