[Ultramaroon]

It's not so much inside-versus-outside. Everyone has over-torqued fasteners. Everyone has cross-threaded fasteners. The lesson here is to understand that it's natural to want to get in there an really cinch it down tightly so it doesn't come loose. We must learn to fight that urge.

For newb friends I've had under my wing, I put old screws in the vise and had them turn nuts slowly until they strip. Materials vary. Aluminum is super tricky because the threads yield - begin to strip - more gradually than steel.

Use a torque wrench.

That one will be a bitch. Cut the weld stud down flat. Drill & tap to 6x1.0 mm thread. You might need a bottom tap to finish the job but it's doable. Cut a hex head cap screw to the correct length and clean the threads until it starts nicely.