Hmmmm... I never considered Richard being Jacob. I guess because Richard was talking to Ben once and said something about Ben going to talk to/get instruction from Jacob.
There is definitely
something going on with the whole "not aging" thing with Richard though. I posted on another thread that maybe Richard is going through his own time-flashes. Except that wouldn't explain how he was able to leave the island to go visit John in the U.S. Hmmm.

Richard has been there throughout the different
times we've been shown. He should be the ONE person who knows the most about the island, it would seem. And yet he looked to Ben for leadership, went to John (during John's childhood) looking for someone special, ... I don't know, the more I think, the more questions I have.

And in addition to the not-aging thing, he was able to get through the pylons without injury. What's up with that?!