Muh autism

>BUILD
Try to find a way to break the level limit, there's no way the shitty devs didn't put something like that in when people were capable of breaking the spell cap by getting more than double the spells normally allowed. Once I have the highest possible level, put everything into Automaton racials, Gunner classes, Monk Classes, and a combination of ore creating classes and telekinesis classes. My /fa/ would be a mix between casual wear and aesthetic light armor such as what PA wears, and more brutal and violent heavy armor.
>GUILD
Robots and Automaton racial levels are mandatory. I'd be very selective about what kinds of people I let into the guild, focusing on spying on potential candidates to join my guild and getting to know them. I'd put someone else in charge of organizing events and such because of my unreliability to follow through on obligations to others, but I would make absolutely sure I had absolute power in the end.
>BASE
Space ship, fucking huge one. Take inspiration from many sources and many different people, combine them and play around with them to make good looking and powerful areas, the main motif would be casual but violent. POP would be machines of course.
>NPCS
I would design some according to their respective areas, but the strongest force would basically be akin to the 8th floor and the throne room and Lemegeton. An area that forces the enemy along a predictable, small, and narrow path, with a large and constant barrage of high power high level traps, a large group of golem defenses to pull the enemy into a false sense of security, then a large and powerful debuff followed by an assault by a team of the strongest NPCs there are in a team, working together to destroy the enemies. Other than defensive based NPCs, the rest would be focused on making the base totally autonomous and self sufficient, then development of weapons and magitech. Their personalities would be jury rigged from different sources.
>NW TACTICS
Advocate for everyone else to leave before getting isekai'd if anyone is left, no way I'm risking splitting my power that's a retarded move. Change all the NPCs personalities so that they're all great people to hang out with and take total advantage of the "flavor text becomes real" thing, to make them the best friends, subordinates, and waifus you could imagine without having to go into excruciating detail only to leave some small thing out and totally job. Once that's all set and I'm isekai'd I keep the ship in space, focusing on hiding and magitech development. I would take a trip to the NW and fuck around, explore, be an adventurer, take note of anyone or thing of interest, and spy on the civilizations in case they become noteworthy or dangerous. I would spend most of my time hanging around with the NPCs. I would never touch Nazarick, if they got too powerful I would just start proxy wars by borrowing the intellect of my NPCs or glass the continent.