1. When a Fusion core is spent fueling power armor, the Gatling laser will behave as if it has no ammo even if there are spare cores. This issue can be resolved by switching to a different weapon and switch back.
2. Sturges, as well as other Sanctuary settlers will sometimes teleport onto the roof of the house with the workbenches, and the only way to reach him is by making a staircase.
The cause seems to be from the game spawning two NPC in the same location (one will stand on the other's head) upon fast-traveling to Sanctuary, then one NPC trying to climb in place,
which teleports one of them straight up and they land on the roof.
- Fast Travelling can sometimes fix this issue.
- Leaving a stairway to the roof, then a 2nd 2-step stairs from roof to eve will allow him and others that get teleported up there to climb down.
3. I don't know - better to search at google: "Fallout 4 power armours glitches"