I think we would want a panel to go over the more common or meritous ideas for each thing, and they would have to vote or come to a concensus.
Fluff and extra submissions should be allowed by everyone, and again, the best would stay. Hopefully, but not necessarily, the Empire's fluff would be similar, but not identical to what it is.
How do we select the decision-making panel(s)? Well, they would have to be people who have played for a while, know most of the nuances and abuses available in the rules. People who play frequently, or who play more than one army would probably have a better sense of balance, both internal and inter-army, so would probably make better judges of the rules, whereas the fluff could be selected by creatively minded people, or even voted on by the whole forum.
I think a work in progress approach would be best. Come up with some sort of judgment on an issue, say the halberd,
and then post the judgment for all to see. The board could discuss it more. To it would be added the next such judgment, until everything was compiled. No matter what, they would have to be people willing to evaluate all (or most) suggestions and ideas presented.
I do not think that the entire forum should be deciding or judging on the rules side of the book, because as we have seen some ideas are simply way over the top. Nomination would probably be the best way to select the rules judges, if they are willing.