Perhaps consider the enemies that we would be fighting – not just humans but also aliens… some of them big (Torgoth), some with natural hard carapace (Kralien), some slight and squishy (thinking Arvonian there), and some relatively humanoid. We are definitely considering the environment. I think the idea of some kind of concussive grenade would be interesting for breaching doors. We could also have something similar to the “flashbang” grenades as well.
About the energy pistol/ carbine we might encounter. If we give it a generic enough name and describe what it does, we can merrily skip by the mechanics and physics behind how it work, the same way we do with power use and distances. Ideas for names is what we need. It could be a number or military designation, a manufacturers name, or simply a nickname. We could also have a relatively generic name for alien weapons, or again nicknames. What it does would pretty much be the same as they would all be “energy weapons” of some sort.
I am still torn on the other close quarter weapon for hand-to-hand fighting. A small, standard issue knife is a must in my mind. You could cut wires, pry open panels and doors, use it on screws, stab stuff with it etc. In terms of a bladed weapon, I was thinking along the lines of Mundy’s expertise in fencing (if I remember correctly) that made me think about it. That and films like Master and Commander (and Muppet’s Treasure Island) with the great sword fighting scenes (who can ever forget Kermit facing down Long-john Silver?)
