I have also been experiencing most of these bugs! I have a few things to add:
1) When the terrain tool stops working, it actually acts as if the button isn't working. I play with an xbox controller, and the "x" button is what takes the terrain tool out/puts it away. I've noticed when the terrain tool starts to bug, I can't use the x button to "quick-add" things to my backpack either. Sometimes dying fixes the glitch, other times I have to leave the game and come back in.
2) We have noticed the beacons glitching almost to the point that they are useless. They "fall off" of vehicles an