You don't seem to have answered the questions asked by the other monks above, so I'm not sure if you're actually having permission to do this or not.

If you have permission then it seems that your goal of inserting all the thread data into a database is pointless - it is already in a database on the server!

So, assuming you have permission to copy the details, etc, then you should simply ask the host to export the database for you.

If you don't have permission then spidering the site is probably your best option - if you do it slowly and carefully.

However down that path lies madnes..