This is split too much.. I am fan of both and now I have to browse x forums to keep track of things.. even those that
never meant to be split!
If you wanted to split stuff, it would be better to leave the original Index/Railgun forum with anime only stuff, images, merchandise, QA...
(This is basically stuff that is ABSOLUTELY POINTLES to split.
That is common for both fanbases and should be united.)
...and make ONE subforum for the manga/novel readers (manga, LN, character discussion, fanfics, PSP games..
We have now a lot of activity due to the anime, but without it there were like 10 active people on the entire Index/Railgun forum
Once the anime ends, I will be probably talking to myself in the Railgun subforum..
(You have to think of the future a bit too)
The fanbases here on animesuki aren't that agressive against each other. (it's worse on sites like 4chan and similar).
And you can always ban them if there make problems, so I don't think worrying about the Index / Railgun hate is a problem.
And if you made a Poll and asked how many people that read Railgun / Index manga/novels are familiar with the opposite franchise, I can bet that the results would be over 90%.