Hi, on the centering part, assuming you are building your site from the far left on your BV screen page? As an example, the
http://www.team307.com/rocksboxing.html page is set at 801px wide. But! The widest part of the page is the head image
http://www.team307.com/bv01169.gif at only 661px wide. If you set the page width to 661 & tick the center in browser, all will be ok.
Sometimes a quick way to find out the width of a page is to pop a temporary shape on the page & pull it out to the widest point & read off the px measurement at the lower right of the BV page, & then just delete the shape after you have finished with it.
Good luck.