Well there are a few emulators out there but since seashadow got some attention lately I guess that's the one you're using. The easiest way to edit the sp/silk is in the database. I don't know where this is cause it's different in every version but I guess seashadow using that microsoft access file so open it and go to the character table and modify anything you want. and to update your game to 110 is a bit more difficult. You would need the new client but it's different so you can't use it with the current emulator. It would require a lot of pk2 editing.
and I don't know what you mean by your 3rd question. If it's about multiplayer well it is I guess. You should forward some ports or use hamachi and let people connect.