Wait - squadmate outfits change abilities? I thought they were purely visual. How can I find their effects in-game?
Yes. When a squadmate is highlighted, before strating a mission or checking on the terminal on the Normandy, click the button for information about the armor they're wearing at that moment. Scroll through to an armor that fits what you want for that character
Also, is there a preferred mission order - including DLCs?? I assume do the Priority missions last, right? Or does order matter that much in regards to upgrades and such? I just finished Palaven and now have a bunch, including Leviathan, Omega, Grissom and more.
From Ashes can be done at anytime. The earlier the better to get the most from Javik
Leviathan is available after Menae. I usually play it after thessia
Omega can be completed after completing the 3 missions related to Aria. If I decide to play the dlc, its after Citadel coup
Citadel dlc can be anytime after Citadel coup. I play it after Sanctuary
I'd like an order that most makes sense in the story if possible, or general hints. I honestly forgot so much since my last playthrough.
Not counting dlc? It depends on what you want to do for that particular playthrough. For me, I do the least amount to get Ashley back on the squad.
So this would be my playthrough
Earth, Mars, Citadel, Menae, Sur'kesh. In between these missions, I go back to talk with any character and to do a couple of side missions on the Citadel. Grissom, Rachni or Turian Platoon, cure/sabotage genophage, Citadel coup, Ashley back on the ship, Turian bomb mission if I saved the platoon, recruit Javik, dreadnought, geth consensus, reaper base, Thessia, Sanctuary, Chronos, Earth and finally shoot the tube