

So your choice of Navy or Marines is pretty irrelevant after an hour or two. They're both pretty much the same, the only thing that's really different is the starting stats you get. I usually choose either Navy or Marines, depending on difficulty level. Research in particular can be pretty damned useful, I don't consider it mandatory like those above but it helps a lot and you'll get some fun story out of it.

Other skills that are useful are Repair, Modify, Energy Weapons, Research, and maybe some psi-ops stuff if you want to go down that tree as well. If you have at least those three abilities consistently being leveled up then you can beat the game no problem. Level this up, it's consistently useful and makes the game a lot less unforgiving. Hacking - You can beat the game without hacking, but like maintenance above it's basically like playing the game on a harder difficulty than it has to be. Stuff like the pistol you'll get early on to shotguns and eventually a machine gun, these are all standard weapons and all really, really good. Standard Weapons - The vast majority of weapons in the game count as standard, including some of the best in the game. If you don't have it you might as well be playing SS2 on super ultra hard mode, same with.

Maintenance - Your weapons will break and be useless unless you can maintain them, this skill is mandatory. This means that you can pick whichever you like and should be fine, although with that said here's the stuff you need regardless of class: No matter which class you choose at the start you're still free to level up your character however you want, the starting class only has an effect on your starting stats and abilities.
