I do not really understand what you mean by ';second page down' or 'below a post page'.
Simple:Press makes use of a single, WordPress 'page'. If it is appearing where it should not appear then your WordPress theme is performing some very odd and non-standard processes which is possibly something we may not be able to resolve. Why would your WP theme display a WP 'page' beneath a 'post' as you seem to be suggesting. Perhaps you can supply more information and detail.
As to the width a forum displays at then that is also dictated by your WordPress theme. The forum will utilise as much width as your WP Theme defines for displaying page content.
a link to the forum would be helpful...
with two options, the possible combinations are four... you tried two... what you would likely want is display multiple false and display in loop true...
what are the other options on that panel set to? perhaps a screenshot?