I understand that the wording is not official, however, regarding Maelstorm's SP as we currently understand it to be:

Defense - Kinetic Backlash: Maelstorm can use Impervious. When he rolls a d6 for Impervious from damage dealt by an attack, on a result of 5 or 6, the attacker is dealt 1 unavoidable damage after actions resolve.

Were he to be hit by Psychic Blast, I am assuming he would still get the roll in hopes of damaging his attacker.

Is this correct?

Yes, it's the same as White Lantern Superman's white Impervious.

Can you still roll for impervious even though it's penetrating damage?

Strictly speaking, not only can you but you are required to do so. I doubt anyone is silly enough to make an issue of it, but it's not actually optional.

If we look at the text of these powers:

IMPERVIOUS When this character is dealt damage, roll a d6. On a result of 5 or 6,
the damage dealt is reduced to 0. On a result of 1–4, the damage dealt is reduced by
2.

PENETRATING/PSYCHIC BLAST: Give this character a ranged combat action.
Damage from the attack is penetrating damage.

Then the rulebook says about penetrating damage:
Penetrating damage is damage dealt that can’t be reduced (such as by the toughness power), but can be evaded, ignored, increased, or transferred to another character.

So basically what it comes down to is that Penetrating/Psychic Blast does not specifcally ignore Impervious, it just negates the damage reduction part of Impervious, and you would still get to roll for Impervious (which helps White Lantern Supes, Zenhattan, and now Maelstrom as well).

Interaction between Psychic Blast and Kinetic Backlash

Die Roll - Results
1 to 4 Impervious tries to reduce Psychic Blast by 2, it cannot
5 or 6 Impervious tries to reduce Psychic Blast to 0, it cannot. Kinetic Backlash now deals 1 unavoidable damage

I was wondering if the Kinetic Backlash would trigger Mystic damage if Maelstrom successfully rolls Imperivious on a Mystics/Crossgen/Arachnos figure.

No, Mystics only activates when taking damage from an attack. The 1 unavoidable damage from Kinetic Backlash is not an attack.

Hey everybody,

I just went back to this thread and noticed I never said thanks for the help so...

Thanks everybody and ninja rep!

Ahhh! The best kind of Rep!

If maelstrom uses protected, he cannot also roll for for impervious can he?
Ya know to try and feedback damage whoever targeted him(say with psychic blast.)

Sure he can. From the PG:

Protected and Impervious both function against damage dealt. They can be used in either order.

So roll first and then pop Protected if the roll fails.