If your experiencing crashes when entering Tranquility Lane or Oasis I have a fix. I thought this was just an isolated issue I was having because I run windows on a Mac but I recently found out that others are having the issue. The reason for the crash is the Speedtree data in the cells in question. Sesom and I spent over a month trying to figure out why I was the only one having this issue and only stumbled on the fix by accident.
This is not a bug inherent to TTW itself it is a bug because of specific hardware that any given user may have. the fix removes the tree shadows and the moving leaves on the trees, trees may not look as good as vanilla FO3 but, you will be able to play the quests and continue your game without issue.
If you crash when after entering the TQL pod but, before the load screen or on entering Oasis this fix may help you. It works for me and casputin so I no longer think it is just an isolated bug.
Hope this helps,