I think I will try the console trick tonight to warp him to GN!
I set my bar up in a nightclub arrangement in my Sanctuary mall...those banjo-twanging disco junkies will defend it to the death...Buddy is safe.
Edit:
Sanctuary attacks can come from the four cardinal directions, with the main bridge attacks spawning inside the boundary on your side of the bridge. Also, synth attacks can spawn anywhere in your perimeter, and friendly fire can damage gear and crops.
I've had five attacks on Sanctuary in 300 hours playing. Two from the west (Super mutants, gunners), one from the east (gunners), one from both north and west (gunners), and one at the friendly side of the main bridge (ghouls). Plus I had one synth infiltration that got capped before any damage was done. Plus, one attack that I wasn't at home for.
He stopped outside the castle for me, but was moved inside then I was away some days.
As has been said. If there's a bar nearby, he walks there. So you kind of can set him a homing beacon by building a bar at your desired destination.
He also stuck close to the trading post I set up, the one you can get from Bunker Hill to link caravans.
Yes, he goes there occasionally, but the bar certainly is more attracting, since he makes for the bar after a few minutes at the post.
Was really annoyed that I had to sell it to finish the quest. I like to keep the quest log clean. He looked nice next to the bar.
I would kill the guy who gave me the quest but that would be one less merchant who sells shipments of screws. Guess I'm stuck with the quest in my thing forever
For some reason, when I FT'd back to Sanctuary, I saw Buddy wandering up the main street again, even though he'd been happily parked next to my bar...I had just built my Bunker Hill trade post, and he walked right into the cinder blocks and stands in the corner.
Shame he doesn't have a laser on his head for settlement defence.
This might be me being nutty But I give him power cells, and flamer fuel ammo.... And he does seem to use both (not that they go down but he lasers and flamers without actually giving him the weapons like other npcs)