When a character takes more than three wounds do all of the wounds apply for a penalty? For instance if a character somehow took 10 wounds would that character have to make the roll at -10?
Nope. The rules state that wound penalties are capped at 3 wounds:
Each wound a Wild Card suffers causes a –1 cumulative penalty to his Pace (minimum of 1) and to all further Trait tests—up to the maximum of a hero’s 3 wounds.
This is further emphasized on the statement before:
Wild Cards never have more than three wounds—anything beyond that is just considered three wounds and Incapacitated (see below).
Anything beyond doesn't get counted. So in your example of 10 "wounds", only the first 3 get counted.
No, the number of actual wounds you take never exceeds 3. Anything beyond that is just considered 3 wounds and Incapacitated.
For example, lets say you start out with no wounds, but are unlucky enough to take 10 wounds worth of damage. To avoid Incapacitation, you would need to soak 7 of those wounds, but remember that the Soak roll does NOT include penalties for the damage you are rolling against. That means that in this case you would make your Vigor roll at no penalty at all, as you currently have no Wounds.
Lets carry the example on and say you managed to Soak only 4 of the wounds. Although you are left with 6 wounds worth of damage, you are actually left you with three wounds and are incapacitated. You then need to make your Vigor roll to see whether you are injured/dead, which this time would have a -3 penalty for the 3 wounds you have just taken.
If you take additional wounds whilst already Incapacitated, you have to make an another Vigor roll as if you were just Incapacitated.