As to= 关於/至於

e.g. As to that, they haven't decided yet.

关於那一点,他们还未作决定。

As yet = 迄今为止

e.g. As yet, we haven't received his reply.

(迄今为止，我们尚未收到他的回复。)

Leave go of that rope!是快远离那条绳子的意思。