A working lightsaber would make you rich for a week until people started accidentally chopping off their limbs and suing you.

“It’s a sword. They’re not meant to be safe.”

Probably be a really useful piece of industrial equipment, not just a really strange weapon.

It's just a fancy plasma cutter. The defining feature of a light saber--being able to stop other light sabers from passing through it--seems of limited utility in an industrial setting.

Well, from those 3 a teleporter would probably have some economical use, the other 2 not so much.

Besides, "probably impossible" seems to be a large overrating of our knowledge of superconductivity.

You don't think there would be an economical use for FTL travel? I mean I guess it depends on the details (it requires a spaceship that is a billion metric tons and requires a dozen working fusion cores to power it to get to 1.1C for example), but I can imagine a ton of uses for FTL technology.

Transporters would be more useful in a day to day setting, but that doesn't mean FTL is academic.