Can Vader move twice, Force Push to bring someone into melee, then execute a Relentless attack? Or does the attack have to come immediately after a move, with no other actions (free or otherwise) in between?

Relentless triggers the free attack immediately after the move action so no you couldn't use Force Push and then attack.

If you were in Range to perform the theoretical Move-Move-Push-Relentless Attack.......

... Couldn't you theoretically Move - Force Push Closer - Move/Relentless Attack .... anyway?

I guess not... The range on Force Push is kinda limited I guess.

Relentless does not proc on Force Push.

5 hours ago, nungunz said:

Relentless does not proc on Force Push.

Did I misread Force push as a free action?

6 hours ago, Drasnighta said:

Did I misread Force push as a free action?

Sorry, to be clear. Move -> Push -> Move into Relentless would work, but I think this would be a rare occurrence.

Move -> Move -> Push will not trigger relentless as Darth Vader is not performing a move action. The target is performing a move action.

7 hours ago, nungunz said:

Sorry, to be clear. Move -> Push -> Move into Relentless would work, but I think this would be a rare occurrence.

i would not say that this is a rare occurrence.
Don't forget that you are doing the move. And that you don't even need a line of sight to the unit. You can catch a unit that is hidding, move it around and with the cohesion even move him further around. Maybe far enough for you to get into range with the next speed 1 move.

And a range 1 is further than a speed 1 move. You might be in range 1 but not within melee range at speed 1. Thats the drawback from Vader with his slow speed. This little "push" might be enough to get into range.

11 hours ago, nungunz said:

Move -> Move -> Push will not trigger relentless as Darth Vader is not performing a move action. The target is performing a move action.

Just to clarify, the opponent is not performing a move action.