The Faceless, as you put it, is related but.... well, how spoilery do you want things, really? Can explain it but want to be kinda sure how much you want to hear. The Battery Plant and Hathor are nice because they indeed more sidequests than much else. Hathor is also nice to go to because then you can start accessing their boat dock, which I always kinda preferred to trains.
The wiki map will make sense once you've actually been further into the game. If you're new, go on and do the battery plant and hathor stuff, but be aware you might not be have the skills to easily Finish the Hathor questline, as the last guy and his area may be problematic if you don't have traps/persuasion.
Me? I, hrm, I probably did those two side quests, and then trail-blazed walking paths to the other main hubs, such as Rail Crossing, Foundry, and Core City. You can take trains, but for first times, I always liked walking first, to in part clear out/loot things en route and sell when reaching the destination. The under tunnels, where Lurkers are, were also fun to clear out and easily traversed long distances with them (It is hilariously fast to get to Core City if you know where to go in the walkway tunnels). The Faceless situation at Rail Crossing is not a bad choice, either.
Just be aware, that if an a situation seems too difficult, you can always just back off, go xp something else and return after a few levels when you got more skills/better equipment.
