Can Vayne peel away Talon?

Talon's E is a blink. She can hit him with E after he is on top of her.

Can Vayne peel away Talon?

It's possible: especially if Vayne starts casting Condemn before Talon commits to all-in her. I've actually Condemned a Warwick out of his Infinite Duress as Vayne before, time Condemn correctly and you can really screw with a lot of champions. Or, you know, condemn them into a wall and then Vayne can 1v1 the likes of Xin Zhao and win. If Vayne can anticipate her opponent's actions and manage to get a Condemn bolt mid-flight when her target is jumping on her, she's capable of quite a lot.

That said: allowing Vayne to do that comes down to missplays with champions like Talon much more than Vayne's personal outplays. Condemn is an extremely average medium range and takes a fair bit of time to cast, where something like Talon's blink has notably more range and casts instantaneously. If Talon looses focus and gives Vayne ~0.5 seconds for free: he might be in trouble: giving Vayne enough time to Condemn him after he burnt his initiation, if Talon doesn't combo correctly and Vayne has ~0.5 seconds for free she might Tumble out of the way of Rake, and it's possible to avoid the second hit of Talon's ultimate.

Anyways: Vayne can peel away Talon. She probably won't.

She can. If she buffers her E on him and them he blinks in, she will knock him away immediately. That's a very important skill on Vayne against all assassins.

If he is not fed and early enough in the game. If he already kills her with R+W, not really.

Depends. The more fed he is, the less spells it takes, the less chance she has to E.

Her best bet is R+Q and E him when she's gained some distance. But even then it's a matter of "Did he Q already? Did she tumble in his W out of it?"

my deadmans plate 2nd item vayne can