whiskers54
Also how do you tell if mods are or are not affected by updates from Bethesda?
When they don't work anymore.
You basically have to take into account what the mod does or does not affect in the game world. Most are not affected by updates or bug fixes. Mods like Homemaker (a truly epic mod) will continue to function after and update, but will not affect or add more items until it's been updated to reflect the new content. So the majority of the mods will continue to work just fine even though they are no longer being supported or updated by the mod author.
And to answer your first question, Locksmith is not affected by the version updates because it affects things that are already in the game. It's possible that if new lockable objects are added it won't affect them. But I don't think it works on and item by item basis. I think it affects the lock/unlock situation that all lockable objects address.