1. Leased lets you run the board for 1 year, Owned lets you run it for a lifetime with a yearly renewal fee of $30 for updates. (owned will be the cheaper route).
2. You can only run 1 board per liscence. If you want to run a music board on one site and an escort board on another site, you will need 2 liscences.
3. Its easy to install the board itself with some basic reading and you get free support via the forums but if you want Vbulletin to install the software for you, they charge you a fee for this extra service.