I agree with Kiran, all answers are correct, I did the upgrade from BE2010 to DLO 7. If you try to upgrade from BE2010 to BE2012, the system stop the upgrade and show a warning with two options: unistall the DLO; or upgrade to DLO 7, before to upgrade to BE2012.
In reference to point 4, the install must be over BE2010 this make an upgrade and all still intact.
About point 6, I found an issue in DLO under BE2010, if you have Win7 64bits and Office 2010 64 bits, the Outlook doesn't work fine. The system send a message thinking that the Outlook 2010 isn't the defualt mail system. This works fine in the DLO 7.
Only that I don't like in the DLO 7 (that is the same as Netbackup DLO 6.5), is that this version haven't the option to limit the bandwith use in the profiles, that is present in DLO of BE2010 it is very useful when the users working under VPN.
Carlos Espinoza.