The IP boards look interesting. I suppose it all depends on how much work you want to put into the forums, and if the community would be up for the change. I have seen some really cool themes for other games using these forums, as well as nice themes with no pictures, or non-game pictures.
I don't really see anything wrong with the way the forums are, currently, but I would like the look updated to reflect the game (New logo), just my opinion.
I don't think making registration harder is a good idea.
I would either go for option 1, or 3
Also, looking forward to the forums being opened up to the whole community
