If you upgrade - it'll only be Opera 12.17, that's all.
Yes, there are settings in "Preferences" there (I'm not with Opera now, can you stroll there yourself, please).
is there a eay I can be notified when someone answers my Opera Forum?
Go to your profile (upper right corner) and choose the "Notifications" tab: you can choose to get notified in three or more cases - including your threads, starred threads, etc.