While Anima is in charge of doing the battle rules, I am in charge of the non-combat skills
Anima suggested a good way to handle them, instead of "skill check with a percentage of success" like was the first game, it will be different. There is still the skill check, but is a value you must match otherwise fail. However, you have a finite resource to temporarily increase the skills of any characters (have to work out in the plot exactly what it is, some sort of super energy) during missions.
So it's up to you to choose in which skill check you'll use that "boost". Obviously, it will not be enough to "skip" all the checks, and it will depend on the difference between the required skill value.
Mission A, there's a Medicine skill check of value 10. Your best character has Medicine 10 = you pass it.
Mission B, there's a Medicine skill check of value 10. Your best character has Medicine 5 = you'll always fail that option, unless you "buy" the difference, subtracting it from the finite resource pool. That value will change based on difficulty level.
Of course like in the first game, for each situation there'll be at least two choices, if not more.
Now about the real question, I want to narrow the skills into 8 non-combat skills. Doing more would be too much, since even in this list there are already some skills that could be similar for certain situation (like lockpicking, could be either sabotage or science even if this last one would involve more hacking than lockpicking). I have this list:
1.Physical (jumping high, resisting impact, etc)
2.Survival (like finding food in a inhospitable environment, scouting, etc)
3. ??? (was Psionics, but I'm looking for another skill)
4.Charisma (leadership abilities, convince others of your ideas)
5.Science (hacking a terminal, fixing a device, etc)
6.Medicine (healing someone, human/alien anatomy knowledge, etc)
7.Sabotage (both using explosives, or stealth to infiltrate)
8.ESP (empathy, sixth sense)
the one I am not sure/I don't like is Psionics since is too vague (they could be used for anything, like healing or hurting enemies). Was wondering if you have any suggestions
Lockpicking would fail under either Sabotage or Science.