Here is one of his abilities:
"He may also spend an action to move a pawn to any city that contains another pawn."
Do the words "a pawn" and "another pawn" include himself? For example: I would be able to send myself to one player, share knowledge, then send myself to another city in a different player, and share knowledge again. That would be 4 actions. It sounds a little too good to be true.
How do you guys interpret that ability? Has there been any official interpretation on it?
Yes, you are correct on all accounts.
The dispatcher can help people move quite quickly. But don't forget that "share knowledge" can be done only if you have the card for the city that you both end up in (unless one of the other players has a special ability allowing otherwise).