I think you guys might be missing some pretty obvious things here...
As usual, your points are all spot on. Planetary infrastructure is rarely random, as laying down a city is an expensive operation, no matter who is supplying the funds.
Considerations:
1)
Terrain is key. Airfields are usually situated in open country, primarily to take advantage of prevailing winds but if there are residences or buildings nearby, there are safety and noise abatement concerns, as well. Having aircraft on approach descending over the suburbs will garner you a lot of complaints, even though your runway was built decades before those suburbs existed (Yes, I was born in one of those towns...and you'd figure the people buying those houses would have noticed all the jets flying overhead...)
2)
Note the supply chain. The raw materials from the (A) mine are sent to the (B) processing plant then to the (C) manufacturer (stage 1)...etc... These could be all on the same world (cheapest), a series of worlds in the same system, or spread out among multiple systems. The same goes for food, water and other goods. A sustainable colony doesn't need shipments of supplies needed for its inhabitants to live...but...consumers place higher value on products not normally available locally, such as tobacco, coffee, tea or chocolate (things that I needed a ration card to buy on post in Germany as a soldier).
3)
Tie it together. Okay, you establish a raw material mine and set up operations. Where do the workers live? A tent city? A trailer park away from the noise and smell? Corporate apartments? Is there a commute? What is the distance from (A) mine to (B) processing plant, if they are on the world? The processing plant might be closer to the main power supply and better living quarters, and likely closer to the air/space port. People like to live close to work, so expect urban sprawl in the form of apartments until people earn enough to move to spacier suburbs.
Despite being centuries in the future, the BTU is surprisingly low-tech, which is fine, because most players can identify with low-tech. That being said, there is still the principle of diminishing returns, you could plow a field with an ox-drawn plow and it would be cheap, but the time and effort would only allow so many fields to be plowed in a planting season, which is why one Medieval farmer might feed up to a hundred people while a modern farmer could feed many thousands.
So, what do raiders go after? Unless certain raw materials are extremely rare to find (an impossibility in any system), the most cost-effective way to steal something is to let somebody do all the work and then take the finished product. Off the production-line equipment, vehicles, battlemechs, harvested food, all would top the list. When you steal a battlemech, you aren't just making off with an expensive product, you are stealing the value of its materials, components and the labor invested in creating it. Whether you are stealing something on behalf of a House or for blackmarket sale, you are investing your time, assets and even risking your life and freedom for some gain, so a raider rarely expends more than they will profit -Governments do that kind of rubbish, under the canopy of war, where the side that wins does so by costing the enemy more than the war costs them.
Location, location, location... A system in the center of a House's dominion is going to have less chances of being raided than a border system facing a hostile faction. Then of course, that world devoted to mass producing plastic kitchenware isn't high on the list of strategic targets, unless that world by its location, is itself a strategic asset, where raiders would just visit to break things. A defender has to weigh the value of an asset, such as factories and warehouses full of valuable stuff, against the inevitable expense of guarding those assets. A strong enough defense might deter many potential raids, to the point that a lack of raids might raise questions about why there are so many defenders in the first place, especially among those footing the bill. The presence of nearby government assets effectively lowers those costs.
Motivation Outside of war, the strongest motivation for raiding is profit, which also means a raider must also have a point where they will will just cut and run, rather than incur losses from which recovery is difficult. As with many mercenary units, some may take damage that costs too much to repair so they wind up accepting lower-paying, minimal risk garrison contracts until they get back on their feet. High-risk can mean scoring big but could also mean disaster for some.
From one Creator of the Universe to Others... Over the decades I have run dozens of campaigns, many extremely entertaining and while I prefer to construct a "thinking man's" scenario, very few of my players campaign in order to think, preferring to shoot their way to victory. With that in mind, a GM has to set various levels of success for scenarios: A) Basic victory: Turn back raiders; B) Morale victory: Send raiders away with bloody noses; C) Positive victory: B with salvage; D) Total victory: C with prisoners; E) Resounding victory: D with valuable data to find raider's main base...etc. A thru C are pretty easy with just muscle; D and E take a little more thought and noncombat abilities, as prisoners and data are usually handed over to authorities at higher levels.
Most of my players always went for the lower-hanging fruit and only aimed their sights higher under the leadership of NPC commanders, sadly. I've run campaigns where none of the players wanted any kind of authority at all and intentionally designed their characters to be totally useless as administrators.
Sometimes, a GM has to dumb-down a campaign to suit the players who only care about combat and nothing else, which made running Clan campaigns hilarious, when the ToP winner was totally incompetent as a unit commander...
