I'll answer what I can:
1) The YouTube videos that the iPhone uses are H.264, not Flash video, thus YouTube needs to re-encode their videos for the iPhone. Many are done now, more and more will be done over the coming weeks/months. Reencoding YouTube's library, if they even do their whole volume, will be very time consuming.
2) Contact pictures are synced from the Address Book app on your Mac. You can copy them from the Address Book and save them in iPhoto, then sync the library. But currently there's no way to cross-reference the photos.
3) No copy and paste function at this time.
4) Are you absolutely sure its correct? No typos? Make sure you have the correct username and password(s) in the appropriate boxes in the mail account setup screens. Unless Earthlink is doing something funny, any standard POP box should work. If you use this Earthlink account in Apple's Mail app, use iTunes to transfer and sync the mailbox settings instead of entering them in manually.
5) What you request would require a GPS receiver in the iPhone, which it does not have.
6) I've never used that site, so I'm not sure what its supposed to look like, but you can manually zoom in on an area of a webpage by using the pinch gesture on the screen.