I can't answer the 2nd question, but, as far as the first question is concerned:
"Does Data Protector 7 allow you to be able to configure backup jobs - via the object properties to exclude files /folders that haven't been modified in over 3years??"
Data Protector has no mechanism to do this. You can exclude or Include files and folders, but it is all or nothing
DP does give you the opportunity to do either Full or Incremental backups, to use the option "Use native Filesystem Change Log Provider if available" but, this will affect only files that have Changed since the last Full Backup, pretty much the opposite of what you want to accomplish
I think that the only practical way to do what you want is to move the older files to a different folder, and not back up that folder