When using this card, if the ship equiped with this is being shot at is is concidered obstructed?

No. Only what's in between the attacker and the defender can count as a possible obstruction. An obstacle or another ship with Tactical Jammer.

Ok i saw some one playing it as a obstruction in a casual game and it didn't seem right

Stealth Device adds 1 Agility and can get knocked off by a hit and costs 3 points. Why would you be able to add 1 Agility for 1 point?

It didnt seem right when i seen it but that was how they played it