If V Batman (legacy) is on an object, thus in stealth thanks to the bat team ability, and I move Ares next to him, can I outwit Batman's outwit, or do I have to attack him first in order to see him?

You won't be able to outwit him until you get him out of that hindering. When you move Ares up next to him, yoink his object out from under him, outwit his outwit, then crank him the next turn.

Even if you are adjacent to Batman, he is still in Stealth. Therefore, you cannot draw LOF to Batman and Outwit him. As long as he is on hindering or behind it (when attacking him at range), you cannot see him.

what if I move a grounded outwitter next to him, like Red Robin. My question is: Do I have to attack him in order to see him, or can I just outwit him if I am next to him?

Even if you attack him, he's still going to be in stealth. It's a weird rule... you can attack him (in close combat) but you can't see him. The problem with Batman is that he NEVER loses his stealth (because of his Team ability). If he's standing in hindering, you'll never be able to draw a line of sight to him, even if you're right next to him. You need to take that object out from under him somehow, or knock him off that object.

You can Outwit him if you have Outwit and either the Ultimates or Superman team ability (or you can copy it).

so if he's standing on a bush, I'm screwed? Can I RS him with a flying fig if I base him...?

Oh yeah... that too. Like the new sig FJ... and that avatar is sweeeeet.

No. Any ranged attack (and Outwit) requires LOF. If a character has Stealth or the Bats TA, you cannot draw LOF through hindering terrain. No LOF, no attack (or Outwit).