Slide Search Engine

I am in the process of evaluating 11 repository solutions for my project.

Searcher Side:
1.  Can I replace the Slide search engine with my own?
2.  Does your search engine look through actual document contents - 
as a background process or at the time of the actual user search?
3.  What FORMATs of actual documents does your search engine look 
at?  (Ascii, Microsoft, PDF, etc.)
4.  When searching the contents of a PDF file, does the background 
process, using OCR, create an additional file in another format? What format?
5.  Does your OCR routine search FORMATS other than PDF? If yes, what 
formats can the OCR search?
6.  What are the resolution requirements for your OCR routines?
7.  Can I change the GUI to a) add functionality or error checking 
and b) to look personalized with CSS?
8.  Can the search engine search using both requested metadata 
element values and keywords from the document contents?
9.  Can I start with keywords from the document contents and then 
later filter the results using user inputted metadata element values?
10.  Can I start with user input metadata element values and then 
later filter down the results with document contents?
11.  After an initial search, can I refine my search by only looking 
at the results of the previous search?

Thanks,
Belinda