Gregor, I'm out of town so I can't help much with out the computer I'm usually working. If you want to, you can check the first messages from my profile -- there's enough info about how the search and the openfts-driver package relate. Basically, yes, you can index files as well as content in the database with the current search packages. The search package is very general and the only thing you need to do is write an implementation for the FtsContentProvider contract. OpenFTS-driver only provides an implementation of the search engine contract -- you could if you want enable the search package to work with some other engine, htsearch, swish, etc by writing an implementation of the search engine contract.
I'm sorry that I cannot be of much help now. If you can wait until the end of next week, ping me again about this and I'll try to provide you with more information.
