Just wanted to share that I can now FTP to my Pre 2, Veer, and TouchPad.
Connect your device via USB and use webOSquickinstall's Linux command-line function, then copy-paste the commands from page 1. After that, just switch to USB drive mode to copy the id_rsa file to your desktop, configure Filezilla and you're done!
No mess, no stress! :P
Update: Holy CARP! Now I'm getting that "Network error: Connection refused / Could not connect to server" error on my TouchPad. Does this thing have a firewall or something? Or was it because I restarted it?
Solution Update: After reinstalling everything and still not getting anywhere, I figured that this must be a service problem. So going through OpenSSH's wiki at webosinternals, here's what did it:
Just did it via webosquickinstall's commandline function. I'm back online