Google Desktop Search is flawed

I use Google Desktop Search (GDS) and find it invaluable. The "Browse Timeline" option is really useful but I find that I have to organize my work to suit GDS because it's missing some really basic configuration options.

I only want GDS to index data files, so I have set up a drive just for data and I exclude all other drives from the GDS search crawler. GDS can't recognize some of my data files yet they are still indexed and they'll never be found in any search except by filename - an option to exclude specific file extensions would solve this.

The other problem is email. I have to have Microsoft Outlook switched off when I'm not using it. If I leave it on I get spam (which spambayes takes care of) then GDS indexes the spam. So, to suit GDS, I stop GDS indexing, check my emails, delete the spam, then start GDS indexing. If I'm unlucky I'll get some spam delivered while I've left Outlook on with GDS running (so it can index the email) - an option to exclude specific email folders would solve this.

Because GDS is so valuable to me I change the way I work to suit the software. I imagine that the two (fixes?) enhancements I require wouldn't be too much trouble to implement. How do you get software improved when it's free?