Just to make sure I've got this right...

• I attack Quickdraw with (for example) Ketsu Onyo, at Range 2, from my mobile arc.
• The attack hits, causing him to lose at least one shield.
• Both Quickdraw's attack and Ketsu's Shadow Caster Title trigger, but...
  • At Step 8, I resolve the tractor beam token, and move Quickdraw onto an asteroid (rolling for damage as normal).
  • At Step 9, Quickdraw resolves his revenge attack ability, but cannot attack because he's on a rock.

Does this sound correct to you folks?

Yep. Step 8 is non-attack effects such as a tractor tokens from Shadowcaster. Quickdraw has been confirmed to work in Step 9 when the damage comes during the attack. Tractoring QD onto a rock is a potent way to strip shields without taking return shots.

Folks may have noticed Simeon Delapina using Tractor Beam to toss QD onto rocks in the final.

Next question... for purposes of the Shadow Caster title, if Countdown uses his ability to take stress + one damage instead of the full attack damage, from a technical standpoint, the attack as a whole fails, right? Meaning no Tractor Beam shenanigans?

Also correct. Countdown's ability makes the triggering attack miss.