Here is the review of http://www.projectorscreenstore.com
Well it seems you have done a lot of work on this site and it's paid off. Good work. You have some great grankings with your main keywords. Here are some additional suggestions:
1) On your category naming, you might want to consider adding the word "screens" (or whatever the best word is) to the categories. For example: Electric Projector Screens, Floor Mounted Projector Screens. Although you are ranked well for many of the categories, some aren't as high, such as Portable Projector Screens. Some people choose not to do this because of aesthetics (which is fine if they are willing to sacrifice the rankings) but it does add optimization to the site.
2) Then consider changing the category page names accordingly. Your Manual Projector Screens category would then be named /manual-projector-screens.html instead of the other way around you have it now.
3) Consider using all lower case letters in page naming. Unix/Linux servers do treat capitalization differently and almost all search engines run on those platforms. While this isn't a huge deal, I have found some small advantages too it.....and in optimization, a small advantage is worth it.
4) Consider changing your category Titles and Meta Tags to include the 3 main phrases for that keyword. For example, for your Manual section, you might consider the title: Manual Projector Screens - Manual Projection Screens - Manual Wall Projector Screens. Alhtough the singular version of these words has more traffic, I typically use plurals for categories and singular for products.
5) Write some content for the header of each category and use those 3 phrases within that content.
Best of luck!