start a thread on xoops.org if u want.. it's still a XOOPS module :) but to answer your questions..

1. yes you can replace the backed up files and your XOOPS will function as before.. except without the ipb core files you will not be able to login or use the ipb module itself (your XOOPS will be fine but it will just stop IPB working)

2. X-IPB admin provides a setting to allow the board to either be wrapped inside XOOPS which will give you the 3 column layout and XOOPS blocks etc (but some editing of the x-ipbm CSS will be required depending on your theme as there's a couple of conflicts in which links and menu colours are affected, but that's easy to solve too)

the other option is to choose not to wrap and the forum will then be like on bbpixel in full screen mode, using that method means that you won't need to edit the couple of lines in the ipbm css file.. it is also compatible with standalone ipb 1.3 themes/skins too so they shouldn't need to be converted before installing them..

you can also choose which registration and profile to use.. ie XOOPS registration and profiles or IPB's registration and profiles.. most choose the ipb method as they're more flexible..

Thanks for that info. I look forward to trying it out.