The only thing I remember for sure is that no character can stop on any blocking terrain. But:

1) Can Leap/climbers move "over it"? Indoors is definitely not allowed, but what about outdoors?

2) Can Fliers fly over it?

3) Are there any case when it doesn't block Lines-of-Fire?

1.) outdoors yes

2.)yes, outdoors

3.)not really... not unless they're not in the way, lol

I believe that giant characters can walk over blocking terrain outdoors but not indoors.

correct you are

3) Depends on the elevation of said blocking terrain: (from the latest FAQ, p. 19)

"When drawing a line of fire from…
• Grounded to grounded, grounded to elevated, or elevated to grounded - if the LOF crosses blocking terrain it is blocked.
• Grounded to soaring, elevated to soaring, or elevated to elevated - if the LOF crosses elevated blocking terrain it is blocked.
• Soaring to soaring - if the LOF crosses the dividing line of indoor/outdoor terrain on an indoor/outdoor map it is blocked."

Grounded blocking terrain wouldn't block a LOF drawn between two elevated characters, for example.

I like to simply think about it like outdoor blocking goes to the same elevation as elevated terrain.... and I always assume that they are exactly 1 story tall buildings.
That's why it would block all LOF passing it EXCEPT elevated to elevated, Giants (and LCers) can just step on on it and walk over it, fliers can fly over it, etc.

maybe picture it just a bit taller than elevated as blocking will prevent you from falling off of a building if blocking terrain occupies the square you would fall into...

Okay, fine.... blocking terrain is 1 foot TALLER than elevated then



...Or would you prefer more like 7 inches?

Does this mean that a soaring character on one side of the outdoor terrain on the Armor Wars map CANNOT target another soaring character on the other side in the outdoor terrain (with the lab in the middle)?

I lost in the championship round at my venue last night because my surfer got blasted "over the roof" of the lab...nobody knew how to rule it, so we used the old IC rulebook rule of rolling it out. I lost the roll and the other guy blew me away. Is this allowed, or is the lab infinitely tall blocking terrain?

That seems to be what the rules you've quoted the other person quoting say, yes.

Because this is a 2D game, there is no "roof" for the indoor terrain on an indoor/outdoor map.

That's what you get for trying to use soaring.