Hi Marcello,
Ans -1 After every system copy/refresh you need to perform follow up activities like installing licenses, Adjusting transport routes, profiles parameters, logon groups. These are called as follow up activities. What Deepak was mentioning is when you take an online backup + archives. You need to recover the system in the target. That is meant to be recovery.
Ans -2 Yes. You can do this for both PRD -> PRD and PRD -> DEV, When the target SID changes. You need to edit the control file and bring up the system with new target SID after the restore. This control file you need to backup to trace in the source which will be in readable format.
Ans -3 It won't work if you backup with version 10.2.0.2 and restore to 10.2.0.5 . in the target you need to bring up the system with version 10.2.0.2 and then upgrade the database to the patchset 10.2.0.5
This procedure is used vastly and you can use it.
Thanks,
Jagadish.