"To play, stun a front row character you control.

Recover target stunned Checkmate character you control."

Can you use traitor to stun, and then recover the same character?

My guess is no, because you need to declare the target before paying the additional cost......correct?

No, I asked this question before...

I think it is because at the point of playing you cannot target a legal character

I guess the simplest way to make the empath loop silver would be...

turn 1-3 any vu guys, preferably stallish...
turn 4 storm (no team-up needed)
turn 5 empath and 1 drop VU guy--->use coercion, revealing blackheart to get everyone teamed up.
netherworld+undeadlegions or some other recovery cards, flip the alley, JUOD empath and loop for the win...

Correct. You announce and reveal the effect and put it on the chain, then choose modes, then choose targets, then pay costs.