Can Clark use his his powers on your character? Specifically, x-ray vision and/or super hearing?

Ye

If yes, what will he see?

Nothing internally, but the scissor holster on her right leg might give him a short pause. Only one pair currently but will eventually have more.

Toko is nervous all the time so her heart rate is probably rabbity to begin with. If he's talking to her alter Jill, she's as cool as a cucumber, unless she's getting revved up. Bloodily. Or sexually. Usually both at the same time, sadists you know.

Both are naturally honest, Toko is a bad liar and does better by omission than with words. Jill has little in the way of a conscious (though that may change slowly) so she won't be affected by lying. But then she usually doesn't care enough to bother doing so in the first place.

Also Toko mutters under her breath a lot so Clark can hear her salt.