"modern" guns exist, but there's basically never a situation where the are optimal (for RPG scale fights). That is to say, guns that can go through any personal protection, and the wall, and the innocent person in the next room.
If you wanted to destroy/ kill everything in a general direction you would use a missile, bomb, or heavy gun or something. If you're fighting person to person you've decided to limit collateral damage.
Even completely evil people are generally aware that they want property to seize and and workers to exploit (or hostages to ransom for bandits). Good guys will follow the same rules, but talk about innocent bystanders.
If you're an underdog, then you're in your enemies city, or a cave, or a ship with defenses. If you're ever in a situation where your location is known, you're exposed, and confronting military: small arms are not going to help you.
Stunning and precision firearms exist, but they have lower rates of fire and require less cover.
Maybe rapid fire or area of effect stuns exist, but are underpowered (as you don't want to accidently hit someone with four full powered stun attacks).
There are two kinds: conventional and laser.
The conventional ones can be made out of metal, or ceramic, or plastic or any huge variety or things. The variety makes manufacture trivial and detection an exhaustive affair. Body armor stops these, although it takes a lot of armor until you're immune.
Laser blades (or other tech to taste). Body armor is useless. These are harder to make and smuggle than conventional blades, but generally within the means of an enterprising rogue (or any PC).
The combination "bad guys have body armor" and "good guys don't have laser blades" could be used to force a non-violent solution, but has too many parts for the plutocrats to make a running occurrence.
Have the geography of hyperspace change.
When routes need to be replaced, they aren't always of the same quality. This means that over decades, traffic patterns (and economies and polities) must adjust. Chronos and Earth are real close in Captain Archer's time, but real distant in Captain Kirk's time.
Maybe each path has a limit to how much traffic it can handle, both in individual ship size and frequency. So the imperial cruiser has less available paths than the small asteroid hopper. This also explains why smaller ships exist for legitimate commercial reasons. Also it gives another reason not to use a bootleg map: the route may be at capacity, and knowing less than it's legitimate travelers, you're most likely to step in the consequences.
I'd also like to suggest the story telling potential of intransitive hyperspace. Going back the way you came is the most boring possible path. If you're into historical metaphor, sailing routes were also intransitive, resulting in complicated interactions.
Regarding energy and fuel
I'd recommend a two stage system.
Fusion plants are massive things requiring cheap fuel, massive capital investments, and institutional knowledge. In real life, fusion is subject to economies of scale a (from what we can guess now) 100 GW fusion reactor would be much, much more efficient than a 1 GW reactor.
Most of that energy goes to making fuel that is more portable and easily consumed. Maybe also charging some kind of super batteries.
Have the trade language define the active part of the setting. Rather than known space, there's "trade space".
Travel beyond is physically easy, but requires chained translation, a lack of safe travel agreements, and paying for stuff with technology that's probably incompatible.
original definition. Not to say you can't use the new definition, but you have no ground to stand to claim the original way is wrong and only the new definition can be used.
While the meting point of water does drop with small increases in pressure, large increases raise the temperature just as with normal substances.
Below the 90 km mark you either get ice or water that's too hot to contain life.