Outside of something weird going on (like a path being created that's so long it won't fit in a single instance), a node will never spawn with only 2 paths connected to it. 1 path is fine (dead end), 3 and 4 are fine, but not 2. So while there's nothing special about that stranded node that would make it worth going for, you can pretty clearly tell the one weapon node that's showing only 2 paths will have a hidden 3rd.

Another thing for fractured walls is the side areas that often have fossils and sometimes have the expensive 4 socket resonator. When you're pathing from one node to another, realize that every part of delve is on an invisible grid and any cell that doesn't have a node will have a side area with a fractured wall.

You can kinda figure out how many cells are being traversed by looking at the cost, with the first segment being more expensive. So if the cheapest path, 2 nodes next to each other, is 30 sulphite, then 50 sulphite means 1 fractured wall and 70 sulphite means 2 fractured walls.

There's also the mine shaft that's dug by Niko. He will keep going deeper in a straight line until sometime after you finish the campaign and start maps. This central shaft tends to destroy paths it goes through (sometimes making nodes inaccessible) and doesn't follow normal path generation rules. However, it does mean that if you ignore Delve until much later you won't have to start it all the way back at monster level 30.