and you can invest a lot in it when you don't have to compulsively invest in ie mercantile, electronics and lockpicking and hacking, which are the real dump skills
Styg chose to make Mercantile useful by requiring a deterministic amount of it to access the great majority of high-quality crafting ingredients, rare consumables, weapon accessories, special ammunition in any quantity, and even utilities (crawler poison stuff being particularly notable). This is a negative incentive, because if you skip Mercantile, your crafting skills will be gimped throughout the entire game. I'll grant that you can easily make do with, say, 60-70 Mercantile, then pop a Hypercerebrix or All-In to unlock most of the special inventories, except Effreitor Hannah's. But neither Hypercerebrix nor All-In grow on trees, and this is a strongly meta approach, arguably even more compulsive than the way I typically handle Mercantile.
I will agree that Lockpicking and Hacking can be skipped. Ultimately, >95% of the loot you'll receive is essentially just extra charons, because anything that's not at least a >130q crafting ingredient isn't something you'll be using past the midgame. I can't remember a single instance during this entire playthrough when I used a piece of generic equipment either looted from the game world or crafted from ingredients looted mostly from the game world—the only exception being a few uniques, such as Rathound Regalia and the Chemical Assault Unit Armor/Biohazard Boots/Coretech Respirator combo (for 100% Acid and Bio resist). Most everything else I use has been made from crafting ingredients and accessories offered by merchants, much of it from special inventory; and even if such things are obtainable without access to special inventories, odds are you'll be visiting a lot more merchants before you find them.
I skipped Hacking on my current build, and only missed out on a bit of exploration; even then, the endoscope could at least reveal many hacking-locked rooms. You don't seem to recognize any value in exploration, unfortunately, only pure meta.
You know what would solve a lot of this? Crafting not being absurdly strong would do it, though it's far too late now to fix it. The power of crafted gear relegates nearly all of the unique gear and quite literally all of the generic pre-made gear to the status of vendor trash. What really bothers me are all those unique sprites complete with weapon animations—for the Tesla armor, Lemurian Security Marine armor, Protectorate Marine armor (even if you wear the aforementioned on a jet ski, your sprite just wears a wetsuit), and others—going woefully underused, as do most of the Expedition leather armor sprites, because they fill the nonexistent niche of the middle ground: fairly high armor penalties and middling statistics, too heavy for fastfag builds, too light for slowfag builds. They also require Super Steel to both raise their quality and unlock their full potential, which isn't true of tactical coats, riot armor, or tin cans.
And in any event, it's not a compulsion, but rather a cold analysis of trade-offs. I'm not willing to trade off special merchant inventories, exploration and alternative routes, extra charons throughout the game, additional plasma core power, and at least one utility slot for the ability to kill lightly-armored enemies in a slightly different way—AP refund or no.
I'm not saying it can't work. I'm saying that I'm not willing to make the trade-off you're referring to because I judge it to not be worthwhile.
