One of the most annoying things while modding Oblivion/Fo3/NV was accounting for followers. There simply are certain situations where it's better for them to not be around. These can include areas where you want a certain mood, that's ruined with a follower right there, or scripted scenes that don't account for them. You could account for the default ones, but never any followers added in by mods. You could somewhat with FOSE but it's functionality was very limited.
Let me explain. I simple ask that they add in something we can use to designate a 'no go' zone for followers. Once they hit the edge, maybe they say 'No way I'm going in there!' or something like that, then they are put on 'wait' instead of 'follow'. NPC's would simply have a flag that could be set to make them act this way. That would allow modders that add new area's, or new quests to effortlessly account for ANY follower, be it vanilla or added in. It would also help Bethesda Game Studios. All of their scripts in scenes that must account for followers (i.e. getting kidnapped by the Enclave in quest 8 of Fallout 3) are somewhat complicated, and could all be replaced by a simple zone or script command.
I don't think many people out there realize how much this would help modders. I hope they see this. Though I doubt that, so hopefully something like that has already been added in. My quest mods go for a more dramatic sense, so the player is often better off alone. This is VERY difficulty to do considering what I have to deal with to account for followers. It often leaves me with no choice but to make some kind of barrier that kills anyone who passes through but the player, then coming up with some excuse for it to be there, and making sure the player knows.
Hopefully someone out there can relate to this, and we can try to get some system in... :/
Gunmaster95