I have not tried to do an xtreme file with more than one page. So it would seem that if you do an html export with multiple pages it will make the other pages with the same name and _2 _3 etc.
If you need different names than I would try to save as what ever name that you want, such as links , portfolio , etc... Then you would have several different .xar files instead of one multiple page file.
Or just take the original html file and then copy and save as what ever name you need. Then you would just have to edit the html.
I don't think the html export is meant to be used as a complete editor but it is great way to make quick layouts and have a nice CSS page that gives you a lot possibilities that you would not have with tables.
So Xtreme html export in combination with a text editor will make you some nice web pages.
Seeing how Xara has integrated some aspects of the 3D program into xtreme, I think it would be nice to integrate some of the options of webstyle into xtreme as well.
I dont think there is any option to optimize on export.
And I love your web site Squeaky