1. All tables in database can have own prefix in names. It is usefull if you have only one database and many projects.
Another installation over existing instance of travsync will remove all data - be sure that prefix for tables is unique.
You do not need install just to upgrade your existing version of travsync.
2. For best results use php extension mysqli to communiate with database. If not sure that mysqli is available choose 0.
3. Engine for storing yours session data, if 1 doesnt work try 0.
4. There is an possibility to integrate forum PunBB with trooptool by editing few lines in source files of PunBB - option disabled by default .
5. Few words about this TravSync instalation - will be displayed in the footter of every page.