回复:但是如果在公司B上班一个或者两个星期后公司A给offer了,
if you think that A works better for you, just leave B for A.
I think B really wants a happy employee who can contribute. If you are not happy there, leaving will be best choice for both parties.
I don't think any problem regarding 信誉 unless B wants to sign you to a 10 years contract or something like that. You think they won't fire you after 2 weeks if they find out that you are a bad fit?