1. How can I customize the Error Message Sorry, an error occurred?
use the 'errorMessage' dojo attribute from the dojo grid control (see dojo toolkit how it works)
2. How can Customize the the hreflinkTitle? It now ony gives the form name
do not use the build-in field names, use @formula code for your own computed values inside the 'columnFormula' property. This is runtime evaluated on every found document and may return a html string in whatever format you like
3. How can i get The current row number
I don't know, but why you need this? you can always make a custom dojo grid function to display row numbers. Another option is here http://stackoverflow.com/questions/16538012/dojo-datagrid-get-the-row-number
4. I can i count the Search results?
Yes, you can call the java component to get the count of results. Use for example :
sessionScope.get("searchResultSet").getAllSearchResultDocs().size();