Can I set a forum option to be always notified of replies to my posts? (as opposed to having to enable reply notification on each single post of mine).
If not, could an admin please configure such feature, if forum software allows?
Seems to me most users would like to know if their posts are answered.

This would indeed be handy, as would a distinction between thread subscriptions and notifications.  On the popular forum application vBulletin, for example, you can subscribe to a thread to receive email notifications when any new posts are submitted, but in addition (and by default), any time one of your own posts is quoted anywhere, you receive a notification in the forum when you're logged in and optionally via email.  The forum notifications are aggregated under a single icon, very much like Facebook's badged notifications icon.