I'm sure most of these questions have been picked over before, so I apologize in advance for that.

1: Do characters with L/C, Hypersonic or Phasing break away from doppleganger tokens automatically, or do you always need to make a breakaway roll regardless of the movement power on the dial?

2: True or false, when you are taking damage from doppleganger tokens, you only take one point of damage, no matter how many doppleganger tokens you are adjacent to.

3: Doppleganger requires line of fire, but it's not listed as a ranged combat action. If Trigon is based, can he still use Doppleganger?

4: Since dopplegangers are not characters or terrain, can grounded friendly and/or opposing characters move through squares with dopplegangers?

5: Are squares with dopplegangers still considered unoccupied terrain?

6: Since dopplegangers can be destroyed like blocking terrain, do they leave hindering rubble until the start of the next turn like destroyed barriers do?

7: Are doppleganger markers removed immediately if Trigon loses the doppleganger power, either due to damage or due to having the power outwitted/countered?

You can use these powers to automatically break away (as well as any other powers/abilities that allow you to break away automatically or improve your chances at breaking away).

(from the "A Crisis is coming - Q&A" thread on the WizKids Heroclix: Rules forum)

True.

(from the "trigon and doppleganger you do nothing?" thread, on the WizKids Heroclix: Rules forum)

Sure, for the reasons you stated. Being able to draw a LOF is different from being able to make a ranged combat attack.

Yes, for the reasons you stated (can't find a quote from the Rules Arbitrator for this one, though, but I'm sure this is correct).

No. Though you can move through them, the squares are considered to be occupied (i.e. you can't place Barrier markers in it, nor stop on their squares).

(from the same thread as answer 2, when answering at the question if Barrier markers could be placed on them)

Nope.

Yes.

Thanks for clearing this up, Drunky. Great info as always!