1) One would compare applicable skills as usual, looking at relative degree if that is what one normally does, including ODF and DDF if they tend to use them. I personally would reccomend my Threshold system, due to my immense bias towards it, in which there is no ODF, no DDF, and wounds are handled as such:
RD 1: -1 penalty for one turn.
RD 2: -1 penalty
RD 3: -2 penalty
RD 4: -3 penalty
RD 5: Out of the fight.

All penalties are cumulative.

I also usually use simultaneous combat, which is just a comparison of combat rolls, with those who roll higher winning. It is explained far more in the combat section of the Fudge book.

2) Strength, Agility, Toughness, Perception. That said, I dislike mental attributes as a rule, if you differ adding them would be fine.

3) Fudge on the Fly would work really well, however a handful of stunts to be designed on the fly (using either the Blood Sweat and Steel stunt design rules or the Diaspora stunt design rules) would improve Fudge on the Fly, given the type of game you are GMing.

4) Plenty, all over the place. That said, its often easier to design something than just mix and match, which would probably be necessary.

Beldar1215 wrote:

The group I'm running for is somewhat young (14-18 year olds)

Best not to let them listen to the Whartson Hall SLIDEWAYS game, then. It is a bit sweary...

At 14 to 18, I wouldn't worry about it. Profanity peaks somewhere in that region for many people, though the region might need extending to the early twenties on the upper end. For the rest, its either novelty as children who see the words as "bad"  but lack any real understanding, or particularly grumpy old people who swear a bunch.