I'm not sure if those builds are ideal, but I'll just share the subs my FC is using for the tasks you describe - Shadygrove already gave a good explantions of the stats, but considering their suggested builds, I'd like to point out that you want Favour to be at 90 (at least that seems to be some sort of sweet spot)

To bring back not-so-rare-items like kamacite ore, I'd suggest a build that focusses on surveillance (so you'll be able to get the desired item) and retrieval (so you'll get more of the item.) The build we're using for that is:
Hull: Coelacanth
Stern: Syldra
Bow: Coelacanth
Bridge: Syldra

You could instead go for a surveillance, retrival and speed build, so you'll be able to send the subs out more often - personally I prefer to send them out every few days and be done with it, though. Our build for that:
Hull: Coelacanth
Stern: Shark
Bow: Syldra
Bridge: Coelacanth

...there are people out there who know a lot more about this than I do, so please take this with the grain of salt that I put them together during an afternoon a few months ago, got fed up with stats and cross-referncing during the way and finally just went with them. There might a lot better builds out there, but we've been happy with those so far.

For minions you want a surveillance of at least 170, is I recall correctly - we're using this build for that:
Hull: Coelacanth
Stern: Whale
Bow: Coelacanth
Bridge: Coelacanth