“Pulser” was a suggestion. Illustrations were cool but I quite liked the baton-shaped blasters that were used in Andromeda. With no recoil there is less reason to have the grip aligned to absorb shock. Ultimate point and shoot, but the badass pistols are more grungy.
If slugs are dangerous to the environment and that is why we need energy weapons. Then armour may not need to be the massive plate-type but more the embedded mesh to dissipate heat. That mesh might also be good at resisting cuts and dissipating crushing blows. That would make the case for a piercing weapon like a shortsword.
Heavy marine combat armour would probably only be used in groundside environments where kkinetic weapons are safe or larger environments where a lot of hand to hand was expected.
Headgear, I like the idea of a heads-up display like the tech monocle in Mundy’s avatar. The headgear as armour makes a lot of sense but visual media avoids it in order to show the heroes faces 🙂
Knife: I have a hard time seeing urban tech beings carrying a knife unless they have some honour code-based need to carry a weapon. (TOS Mirror Universe) I envisage the TSN/USFP as less martial than that. All of the practical applications would be covered by a modern multitool which could of course include a four inch blade. A knife would be reasonable anywhere outside an urban environment or specifically in combat gear.