reminder that diamond prices are inflated and they aren't actually rarehopefully we've fixed that problem by the time we're involved in space attacks
Also take into account that weapons can be both lasers or plasma beams. Have fun making coverage for plasma beams.And if the hull was 100% totally-reflecting mirrors, you wouldn't be able to have windows because light would never enter.
a weapon that utilizes superheated gas in a nongravity, 100% heat insulating environment sounds both terribly inaccurate and deadly to the user
You have to remember that plasma isn't just superheated gas, it's superheated ionized gas. This allows it to be manipulated by magnetic fields and thus be aimed, accounting for stellar wind.
the same fields could be used to make the weapon utterly useless
Not only that, but superheating it in the first place will probably stress the heat radiators on the craft. They're the most commonly forgotten part of spacecraft design.
assuming the manufacture of the ship is using pure cut expensive as forget diamond plating, the laser would probably just produce smaller myriad lasers and dissipate in all directions.
the fourth state of matter is truly as unhelpful as can be
lasers probably wouldn't be weaponized, we'd likely use railguns
this, or we'd still use some conventional weapons because newton's laws are deadly in space.