When Tel gets a crit with Blinded pilot (no attack next opportunity) and gets destroyed (and resurrected by his ability) before he can attack (e.g by other ship or R5-P8 droid), can he then attack another ship? So the crit card is not valid any more?

If his 'destruction' and then 'revival' all happens before his normal chance to shoot in the combat phase, yes, he would get to shoot as part of his ability is that all damages card on him are discarded, including Blinded Pilot, meaning its no longer in play.

When Tel resurrects you discard all the damage cards he accumulated during his first life, so yeah, Blinded Pilot will be gone and have no further effect.

Edit: derp