I've searched and never seen anywhere on the net about this so I figure after years of doing this, I'd share with you how it's 100% possible to make the Mistwatch bandits permanently friendly and use Mistwatch Tower as a hub, but not completely a player home because I assume (I haven't checked in CK) the chests and barrels all reset. I made this video to visually show you how it's possible to do the little mini quest without having to kill a single NPC. Keep in mind this is all vanilla. No mods or console command(s) are required to do this.





Before you do this, make sure you have a high enough sneak level, or you have Muffled boots or the spell Muffle casted on you.

Take the back road that leads around to the back of Mistwatch Tower. You should be looking downwards upon Mistwatch Tower. Sneak your way down into the entrance door of Mistwatch Tower and enter. Make sure you don't attract the Mistwatch Bandit. Or rather, get too close to make them hostile. Run (or walk) up to Christer and begin the mini quest to search and find Fjola. Drop to sneak mode and sneak very slowly on your way out the east exit. Upon exiting sneak along the wall on the left and once you are far enough you can get up and run towards the geysers. The point is to go around and back up, but not back up to the road you took to Mistwatch Tower. Only to the dirt road that takes you to the North East entrance to Mistwatch Tower where a Orc Bandit leans against the wall. Instead stick to the hill on the right side of the dirt road and go up and eventually you will near the tower. You'll get high enough to reach the highest door to the tower that leads straight to Fjola. Note: when you exit the entrance, the Mistwatch Bandit up the stairs to the right above the exit, that bandit will become hostile regardless if you are distant from it. It's the only one that will go hostile if it detects you and the rest will become hostile. So be careful when going around the left wall after exiting.

Talk to Fjola and select the choice to convince Christer to leave. Upon exiting the door, sneak your way to the hatch and enter. Getting detected will cause the bandits to become hostile and it won't work anymore. Once you've entered through the first hatch, you can run your way to the next exit of the tower. The bandits inside are friendly. When you've exited once again to the exterior, sneak your way to the next hatch without being noticed. Again, if detected, it will make the bandits hostile and it won't work anymore. Run your way down the tower. Once again these bandits are friendly. They will not attack you. Even if you try and speak to them. Talk to Christer and tell him Fjola is not here or dead. Optional if you want to give him the ring or not). Run back up the staircase and you'll encounter Fjola. Tell her it's done and the mini quest is complete. If you did it right, you have successfully made the Mistwatch Bandits outside that guard the tower permanently friendly.



Edit: According to UESP (https://en.uesp.net/wiki/Skyrim:Mistwatch) under notes: "You can enter and speak with the bandit boss without starting the quest if you have the Wax key Lockpicking perk. Unlocking the master locked door before the final tower gives you the Mistwach key, which then can be used to open and enter the last tower. Doing this will make all bandits inside and outside of the tower friendly."

Doing it this method would require you to unlock the hatch which is to the left the tower where Fjola is. Upon unlocking it, once you enter in the tower you will automatically get the key and you can just exit and go straight to Fjola. This is a much simpler way of doing it but requires the Wax Key perk in order to do this. If you aren't interested in that perk then the alternative would be to do it the way I've always done it.

