Were you having this difficulty before upgrading to 10.7? I have not been able to reproduce this issue. Also, are you saying that the PNG file you export to is not showing all the items on your map? It should show everything on your map but with as little white space as possible around the actual data.
When you say it doesn't let you print landscape do you mean that it appears to let you print landscape up until the end and then it just prints portrait or does the user interface in the print not let you select landscape once you have changed printers?
I hadn't tried printing the map until after I upgraded to 10.7 so I'm unsure if it worked in the previous version. The PNG file only prints what is on the screen, so I have to select it to fit on the screen, which means that the map is teeny tiny and zooming in just pixilates it. This is of no use.
It lets me select Landscape, but prints in portrait. I was able to get it to finally print in Landscape (by actually modifying the printer's properties) but it will never print the whole map on the page, even when selecting 11 X 17 -- I have one switch which is 2 levels down which always prints on a second page.
It seems so obvious but this tools needs
1) The ability to fit a map to a page
2) The ability to export the map to HTML or some format that can fit the map on a (scrollable if needed) page.