Hi! maybe a silly question. A trooper with SSL2 in Suppressive Fire state is being attacked from outside LoF and ZoC, if he responds to the attack the SF state remains or is cancelled?
It depends on what the ARO is. If you are able to shoot (although it sounds like you might not be able to in your scenario) then you could use the Suppressive Fire weapon profile and remain in the state. Otherwise, if you dodge, hack, shoot a different weapon, etc., then you will cancel your suppression state.
To elaborate on Toadchild's answer: the last FAQ has an entry on how you might be able to be shoot, while not having LoF but within your frontal arc...
If you have SSL2 and someone shoots you in the back, in most cases you can retaliate with a Suppressive Fire ARO, and in this case you would not be pulled out of Supressive Fire state.
I believe the ability to ignore facing is only in SS1, which means the enemy would have to be in your ZoC.
Nope. From the wiki, emphasis mine: SIXTH SENSE LEVEL 2 AUTOMATIC SKILL Optional. REQUIREMENTS In order to use Sixth Sense L2, the user must be the target of an Attack. EFFECTS Allows the user to respond with a Face to Face Roll to Attacks (and only Attacks) directed at him by an enemy outside his LoF and regardless the facing of the user. If the user is the target of a Surprise Shot, he may ignore the negative MOD to his Roll imposed by any level of that Special Skill. Sixth Sense L2 allows its user to respond to Attacks against him through a Zero Visibility Zone without suffering the usual -6 MOD. When attacked with a template weapon from outside his LoF the user may ignore the -3 MOD to Dodge a template from outside his LoF.
Delay ability in SSL1 is required for the skill to function, so that the user can actually see if he is being attacked with the second short skill. Otherwise they'd fall prey to the standard change facing fishing.