I highly recommend Thomas Hoehler's Client Tools for Umbraco application to prune your logs and such.
http://www.codeplex.com/ClientTools4Umbraco.
As for removing items in the recycle bin... that I would approach by either:
A) Try to increase the timeout value in your application pool and/or web.config (hopefully someone knows the settings for this sort of thing)
B) Select nodes in the recycle bin one at a time (ouch!), which is safest
C) Blast nodes with a path that contains -20 (the recycle bin). This is the most dangerous because of the potential for left-over data that might somehow reference those (now removed) nodes. Be sure to backup your database first! Once you are done modifying the database, touch the web.config file to get the application to reload, and umbraco will automatically notice the changes.
Let us know what you try and how it goes.
cheers,
doug.
MVP 2007-2009 - Official Umbraco Trainer for North America -
Percipient Studios