Well, I don't feel like using quotes, but let me try to offer my assistance on some of the previously raised issues (Sorry if any of this has been dealt with already. I did read through the thread, though quickly).
First, the issue with the black border above and below the menu image may be due to your screen resolution (or rather size). The texture is quite wide (2048 x 1024). I play on a 16:9 widescreen monitor and have not experienced the problem with the border (downloaded the mod texture and tested it in-game without any problem). I think this may be because the texture fits my resolution more closely (texture w/h - 2:1, my monitor w/h - 16:9, yours, probably - 5:4). Yes, I know how this could sound kind of dumb, but I think it really is something this simple (though I would have expected the texture to be compressed, not bordered, as the 1.011 menu texture was stretched when I switched to my new widescreen). I highly doubt that mipmaps had anything to do with it.
As for the tree, do you mean a BRF editor? In OpenBRF go to Import > Static Mesh and browse to the file location. BRF Edit is the same if I recall correctly. You'll need to create a material and texture entry for it too.
I am also willing to offer whatever assistance is necessary with the module system (yes, there is a version that has been released for WB, though not the most recent version of WB). This especially includes a single player version of the mod (as this is where I have the most experience). Given the resources, and preferably troop trees and item stats, I predict I could make quick work of it (lord and town names would be helpful too).
Hope that helps.