Depends on how you interpret the 2nd amendment. Different originalist justices will interpret it differently. The current court in their most recent 2nd amendment ruling indicates that their new test will allow many current gun regulations to stand.

If the current conservative justices believe any weapons at all should can be banned (which they said they do—of course they could always be lying) then you have to think they believe a MANPAD can.

I know you can’t manufacture an automatic weapon without a license from the ATF. I don’t know specifically about destructive devices. It is illegal to manufacture explosives, and you can’t transfer explosives to an unlicensed person.

So my guess is no, not without a license that you aren’t going to get unless you have a legitimate business interest, e.g., manufacturing them to sell the the military.

It's really not enough, no. There are literally videos of pilots blocking the light with a piece of paper.

As long as we're talking about regular laser pointers, at worst this mildly inconveniences the pilot.

There have been tens of recorded cases of this every day for decades in the US alone, but not a single recorded accident.

The idea that someone could meaningfully endanger Elon by pointing a laser pointer at his private jet is pants-on-head crazy. What next? Oil slicks on his driveway? Perhaps slowly poison him by idling a car in front of his house? Second hand smoking?