Are there any mods (I couldn't find one) which turn off friendly fire? I'm tired of followers getting in my way and getting themselves killed.

I don't belive there's a way you *can* turn off friendly fire, at least without SKSe. And even then it's debatable.

All damage hits enemies, noncombatants, and companions equally. There's nothing in-game (aside from IsCompanion) that designates one NPC differently than another in terms of Friendly Fire.

A mod using SKSE *might* be able to null any damage to Companions, using the IsCompanion variable, but I'm not sure if the game is coded to allow that.

Setting any companions you like to essential status and then have them ignore friendly hits (for the purposes of agro, not damage - they'll still go into bleed-out status if you hurt them too much) is probably the best you can do to accomplish what you're after.

setessential 1 --> look up their base ID on UESP or use the help console command on the companion name

isessential --> click on them, this will return a 1 if they are now essential

sifh 1 --> click on them, this sets them to ignore any FF-related aiming issues you may have

You could try creating a new hidden perk in the CK that detects when you're attacking a friendly target and when a friendly target is attacking you, then set damage to 0%. (Not sure if one perk could do that; you may need to place the perk on both you and your companions.)

I'm not completely sure if you could do that without disabling your ability to murder innocents or commit assaults, however. It bears further investigation.

Also, remember that your followers are sorta immortal- unless you hit them with a DoT while they're down (or if they're otherwise damaged in the downed state) they can get killed. But Enemies will focus on you once they go down.