When a special power slot says that the character can use X power Y power, does that mean that both powers exist simultainiously(sp)? Example...a character's movement slot has a special power that he/she can use Running Shot AND Stealth, that they are both active powers?

Depends on what you mean by 'simultaneous'.

Yes, the character may indeed use both powers, but not necessarily at the same time.

Like all power interactions, the type of action(s) required to use certain powers may make them incompatible. Also, the timing of certain powers may make them take place/override others.

In your particular example, though, nothing prevents Stealth and Running Shot from being used at the same time (and can be very useful if your character is trying to run up and shoot anywhere opposing PC).

I have a similar question would a Special power with RS and L/C work to leap/climb off a building to running shot an enemy?

No because leap climp requires a MOVE action to activate, while running shot requires a POWER action. When trying to see if 2 powers can be used together, its all in the wording.

ok thanks was in the middle of a match and could not remember the actual wording.

Thats what realms is for!

Which is sad the way the powers are worded. Gambit would be even more awesome if they worked together. For some reason, Batman gets to be insanely powerful based on power wording, but other characters have to suffer. *sigh*

Yes. Be careful of wording of Special Powers. First Class's Beast says "He can use Leap/Climb & Charge. This does not mean he can use them at the same time. Just that he can either power at any time.

Psshhaw! I don't really see them suffering all that much. Having 3 movement powers in one slot is a bonus, not a penalty. Being unable to use them together is fair, not a penalty.

He's the god !@#$ed Batman!

Imagine how insane flash would be if he could use his Phasing and Hypersonic power together....not even right.

Actually he can use Leap/Climb and Charge at the same time - just not the feature most commonly associated with Leap/Climb.
Beast does not get to ignore terrain and characters when Charging (unless some other factor lets him do that), but when he makes the Charge attack he can do so against a figure on a different elevation - that part of Leap/Climb requires a Close Combat Action, which is just what you get at the end of a Charge.

Since this is about 2 standard powers as a special power, can someone explain the reasoning for giving Unus the special power that includes Impervious and Super Senses??

UNTOUCHABLE: Unus the Untouchable can use Impervious and Super Senses.

Super senses is activated when the character is hit by an attack, and you roll BEFORE damage is dealt. Impervious says when a character is DEALT damage roll a d6. So the way it is worded, unus has 1 chance to avoid the attack, 1 chance to reduce the damage to zero and if they fail, reduce the damage by 2.

Too bad Unus isn't a Skrull with Shape Change... he'd get two rolls to force the attack to go somewhere else, one roll to avoid the attack himself, one roll to reduce damage to zero, and then, after all that, he'd get -2 to damage...