[Brutha]

We have so many great, smart readers, it would be a great resource.

I don't think that the point of a forum is to be a resource, any more than a bar or a book reading club is a resource.
A forum is more than pure information. It's conversation and relationship building. It's a plattform that draws people from a community into it and gives the community a structure.

I really dig number 5. Creative idea.

The community from which you draw people should be the global personal development community (or as you label it: people who are interested to hack their life).

That community is a Small World network in which lifehack.org is at the moment one of the main hubs.
Those bloggers in 5) are also hubs that connect to a lot of people.

A goal of a forum is to be a sort of hyper hub. A centralised structure in a dezentralised network. While lifehack.org at the moment practically only connects hubs (bloggers) through featured articles, a forum would more directly connect to leaves (normal people interested in lifehacks without an audience).
Integrating a few bloggers into the forum through 5) increase the reach of the forum hub.

There is also a second phase, one you get your participation. Create structure. Don't let self promotion and spam take over your forum.
Encourage quality posters and try to limit "noise" that nobody wants to read. At the moment the old lifehack forum doesn't look like it's moderated and has quite a bit of "noise" that could be deleted to improve the quality. I remember deleting some of the posts in this forum so they are definitly crossposted for selfpromotion maybe even through bots.

If you are interested in building a community I would also recommand you to check out Research Blogging: Forums - Powered by vBulletin regulary. I would guess that we have a working forum there after some time is passed. That site tries to be a hub for blogs who cite research. It will be interesting how the project turns out.