I read the post and it's amazing you took the hard path. In regard to the product, first of all kudos, and second of all; you may want your users to be able to run analytical workflows. In which case embedding Firebird instead of SQLite might be cool. Just something I thought while reading the docs.
I've never used Firebird db so far. I have no idea how it differs. I will check it out, and possibly include it. QueryStorm already supports 6-7 different types of databases so one more won't be too difficult to add. Thanks for the tip!
I integrated most commercial db vendors and we even ran queries on imported data in a HSQLDB database. Firebird is just way ahead of HSQLDB, and HSQLDB is similar to SQLite feature-wise.
I don't mean it would be cool to be able to export to Firebird. I mean that you might want to use Firebird as your underlying engine :)