Rockas, I would say the problems you're having are theme dependent like I've had. I use chaoticsoul for my theme and the forum was pretty much just the background color since that was what the theme had set. To solve this problem I had to create new styles in the css file and then link to them in the theme.inc file which is in the adaptor>includes folder. I know your problem isn't color related but what I'm suggesting is maybe you should start looking at the theme.inc file for the areas you're having trouble with and then editing them to how you need them to be. You may have to add more to your themes css file in order to make the fix the forum without messing up your theme though.
It's working for me but the only problem with this is that when foulu updates the forum you'll have to re-edit the theme.inc file again as I had to do today. A small problem though when you consider the great possibilities this plugin has over bridging a forum. In my opinion anyway.
*edit* Another oddity, I was viewing the code for the message preview and comparing to the previous version of the forum and it matched 100%. I didn't change the code at all but now my preview is working properly. Not sure why it wasn't working before and is now but it is so that's good.
^Nevermind, I uploaded the old themes.inc file over the new one and that's why the preview was working.
*edit 2* I found the problem with the message preview. In the code it looks like this:
make_request("forum.misc.php?action=preview&message="+document.forms
but in the old themes.inc file, when preview worked, it looked like this:
make_request("forum.misc.php?action=preview&message="+document.forms
So when I removed the amp; from between preview and message the preview worked fine again. I uploaded the corrected themes.inc file just in case foulu is busy and doesn't get to fixing this soon. The only modification to this file is the correction of the preview, everything else is the same as in the zip on the main post.
*edit 3* I have found several other cases where amp; was added in the code where it wasn't present before. I'm assuming the editor may have placed them there but I don't know for sure. I haven't noticed any other functionality being messed up though so I don't know if they are supposed to be there or not. I removed them from the file on my site and everything is working great but I suppose foulu will have to confirm if they're supposed to be there or not. I didn't update the zip I uploaded since I didn't know for sure if they should be removed. I'm also trying to find out where the problem with the scroll bar not appearing the post box is but I'm not a coder so I'm not positive on where to begin looking for that.