Most of what you said is a "sad but true" reality unfortunately.
Also, on the idea if hiring NPCs: that's a very thin line. If done right, it puts some NPCs on your ship, which have no meaning and no influence. And that's unfortunately the best option in this community.
If NPCs will give an advantage, they will be seen as stat boosters and nothing else. And if they do give an advantage, than bet on it, FD will have them have stats and some crew-NPC-metagame will evolve. Including massive complaints on the forum and indeed yet another way of power creep. It's just how the game and community work.
If in contrast NPCs are too weak, you can savely bet several months pay that the community will burst out in tears and demand them to be improved. And your money would still be save if you would bet that FD will cave and do exactly that.
I see NPCs as characters you'd have to actually pay to keep on your crew, and probably have to work to unlock or upgrade in some way. So like anything in the game, if they boost your stats or give you an advantage, then it's one you've earned and paid for, so it can be considered like anything from engineered weapons to NPC SLFs.
I think it would be great to work a real AI and learning element in to each aspect of ship management where you have to put in the effort to train your crew, as well as tying things in with other systems in the game.
For example, the co-pilot could be given charge of pip management during combat, and trained to anticipate the pilot's requirements based on ship states and pilot corrections. They could select targets and kill warrant scan them. They could be tasked with running the discovery scanner in each new system. They could also be tasked with preparing an escape route by selecting a nearby system with a station, and either targeting that system and charging the FSD when the ship's hull/modules reach an amount of damage defined by the Captain, or else only by explicit order from the Captain like "Get us out of here!", but not without the Captain hearing something like "Captain, we need to split!"
The engineer could contribute to requirements for the actual Engineer modifications in the game, or by cooperative effort with the main engineers have a positive effect on RNG for better rolls, or even enhance the effects of the engineering by increasing the positive or reducing the negative aspects of the engineering blueprint.
It would give the game some much needed character if as Captain you see your repair crew come up on the console requesting more power to systems, or other such scenario dependant complaints and comments from other crew.
I'm sure there are a lot of good ideas out there for making use of a variety of NPC crew roles, and personally I prefer the ones that don't simply give +1 stat X or something along those lines. With AI learning, crew becomes more valuable and useful as time goes on.
You could even have elements like betrayal and sabotage depending on crew stats and relations. There are a lot of possible options to consider. The difficulty would be in balancing the best of them.