TBH, 5e hates secret roles. (yes, i know this is not a 5e specific post, just a personal gripe)

There are way too many abilities that trigger on a failed roll or can be used after a roll that this kind of play style straight up conflicts with.

One of the worst ones for this kind of thing is the soulknife rogue's Psi-bolstered knack (that they get at level 3), with both triggers explicitly on a failed roll and refunds if the extra dice if it doesnt make it succeed so you cant even include mystery if the reroll made it a success.

Dex would be super important for them too. Cannons of all flavors aim with dex due to being ranged weapons.

I have issue with almost all of your points.

• Dex & wisdom would be the important stats for sailors IMO (i am not saying strength and con are useless, but just not as important, they would be 3rd and 4th IMO).
• Darkvision wouldn't do a damn thing, its range would barely get off the side of the boat.
• Poison resistance is not disease resistance.
• Some spoiled food would be poison, but some would also be disease (depends on how it spoiled and the food).
• In order for short stature to be relevant to ship design, they would need a completely custom designed ship tailor made for them, which would have benifits but sounds unlikely for what pirates would be sailing. (That being said, a dwarven merchant ship designed speciifcally for their stature would be a massive pain for normal height characters to battle on)
• lower speed means they swim slower too which means going overboard is even worse.

EDIT: dwarven submarines!

• short stature actually hugely relevant as submarines are notoriously cramped
• darkvision means no need for lights in the sub, beneficial for multiple (admittedly somewhat minor) reasons.
• honestly no clue what stats would be important for a sub, no argument here
• toxic gasses less of a problem thanks to poison resistance
• Dont even need to go to the surface, a fully underwater submarine port could be connected to existing dwarven settlements near the ocean with the correct design and planning.
• Also benefits from legendary dwarven engineering.

Both are important, even if everyone is getting lots of action (feels fast), if combats end up needing to be split between multiple sessions, people are going to complain that the story isn't moving or that they have been stuck in combat forever. If people are waiting 30+ minutes for their turn, they are going to stop paying attention and do something else while waiting.

Cuz the sewer pipes are known for being hermetically sealed.

I imagine just checking if your windows are closed, sealing any cracks as best you can with wet towels, and staying inside would be far more effective

Found this applies nicely to my career. Routineish work? Drag my feet and fight myself to do anything. Fixing problems (bigger the better)? Everybody stand back, I got it.

Whole damn system failed due to a database failure that propagated to our secondary host too. Hacked our backup to usable in a day (meeting most requirements, including transition requirements) with a path forward for total system recovery on the main system.

Documentation on any of that though, that was a .. struggle.

One thing that will be the biggest general qol for your new build is likely to get a M.2 NVMe for your games and OS

Civ 6 is pretty flexible and dwarf fortress will run on a potato, basically anything remotely in the gaming market will play them fine. Civ 7 is more intense, but being turn based cpu tends not to be the bottleneck

Do you have any preferences (distro, cpu/gpu manufacturer, etc) and a budget? Most of the games on your list I am familiar with and will run on damn near anything remotely modern.

Lacing direction, with the fairly low requirements (from what i recognize), and assuming you are price conscious id suggest you poke around the used gaming PC market (either gamer friends, or failing that online), which will also completely bypass the tariff issue too.

PopOS is pretty solid for linux gaming and has a distribution specifically for Nvidia too which handles most of the headache with Nvidia if you go that route.

EDIT: Poked around the requirement pages of the ones i wasn't familiar with, i didn't see a single game that had a requirement of anything newer than 10 year old hardware, depending on your friend network, you could get a computer that could play those games well for a song. Civ 7, your 'evenutally' game, is the only thing listed that has strongish requirements, and would be what i would pay attention to if you are aiming higher.

Took me way too long to figure out the graph wasn't telling me the murder rate I. 2006 was ~75%

I can not state my love for this game enough, it may not be flawless, but everyone working on it is doing it for love of the game, and is doing great work.