For the 800px wide issue, the layout is setup to require at least 900-950px wide and is not easily changeable, sorry.
I normally use an Eizo at 1200 * 1600 in portrait orientation, and the main "luminous Landscape discussion Forum" title box is too wide, and goes over the search box and the PM info, since last visit etc. ( I get "Dick Roadnight" without the "Hey"). I will send you a screen shot if you need it. This is OK in portrait orientation.
When there is only one post on a page, the LuLa window shrinks to a small proportion of the browser window... this may be correct,,, but when it happened I thought that I had stumbled on a major bug and took a screen shot to report it to you.
Thank you for all your good work.