It's something that can easily be built by players as well as being a rather safe option. As far as weaknesses go, the only thing you have to worry about is any enemies that can teleport, or phase through walls. Most game enemies will not be a threat to you.

Sidenote: If you don't have anything to scale the walls or minecarts/tracks. You can just build a door into the wall about 6 blocks up. Do not worry as zombies even during a blood moon can not open doors while jumping, so they will just keep jumping up against the door.

For those wondering where the Princess goes, she's a odd one as she doesn't dislike any of the NPC's and vice versa, so she can be put with pretty much any group, however she seems to go best with the Party Girl and Wizard.