I'm sure the oranges are loving this character already...
A couple of questions;
Can I attack a character on through the portal? (My figure on portal A and opponents character on portal B)

Can a double based figure end it's movement so it occupies both squares?

Can you place Blocking or Hindering terrain markers on the portals? (Are they considered clear terrain if occupying clear terrain? I'm assuming they take on the traits of the squares they occupy).

If Friendly character is on Portal A, and opposing character moves over (but not through) portal B, do they have to stop if they don't ignore other characters for movement purposes?

Can a figure move through a portal if another character is on the portal? (I'm thinking only if they ignore characters for movement purposes.)

If I place the Portal in Blocking terrain, can a phasing character (or character that ignores blocking terrain) use it?

I'm sure there's more, but this is what I can think of for now.

Answers in bold.

Another one. If more than one character has a Spiral on their team, can both teams use the portals no matter which Spiral placed them?

Yes, but keep in mind that there will never be more that 2 Gateway Markers on the map at any given time.

I understand that, just asking that as long as you have a Spiral on your team, can both teams use the portals no matter who made them?

Yes. That's fine.

I'm thinking using CW013 Vision with
If your opponent has a Spiral, when your Spiral make her Portal Tunnel, place it in blocking Vision can charge through it, then use the Bat Signal to summon him back. Put two on your team so you can do it every turn by alternating.

That all looks legal.

no if player A place the portals only the figs friendly to player A spiral can use them, because the wording on the card so no player B's fig can't use it because they are not friendly to player A's spiral.

It's a three part thing

So, you remove any on the map, then place two anywhere as follows
Great, now, it says this.
Just says that friendly characters treat squares with Gateway markers as adjacent. Doesn't say only ones created by your Spiral. So if both my opponent and I have a Spiral, those gates are open to both of us.

Nope. You're incorrect.

Puuka gave a nice explanation as to why.

So, Chris answered yes to this one, but I'm not sure that's right. According to Golden Rule #3, The Rule of Occupancy, the only thing that can occupy blocking terrain is debris markers. Since Spiral's Gateway markers aren't debris you shouldn't be able to place one in blocking.

The rules for Dimensional Portal state that the second gateway marker may be placed in any square. I believe that means the RoO is overridden by Dimensional Portal.

Golden Rules can't be over-ridden.

Who do you think you are? Rebutting with your facts and physical proof to back those facts like you're all that.