Forty-BotA little update:
I'm migrating the database from SQLite to PostgreSQL. I started this last week, and did the switchover this past weekend. However, some of the queries are now taking way longer than they used to. I am currently working on this. Availability might be a bit spotty until I can get to the bottom of things. I am also trying to get log importing back up, but that is going much slower than before too. Please be patient for the next few days :)
In the longer term, performance was and is a big problem with the site, even before switching databases. I would love if some more experienced developers could look over my schema/queries and help out.
I'll take a look if you share some slow queries (use postgres' slow query logger) and the entire DDL (pg_dump --schema-only) and put it in a github gist.