All Christians are liable for blessing or can a sin stop blessing?

The answer is: The only reason which may prevent blessing is miss of faith. Non-believing is a sin. So the answer to the subject question is “yes”: A sin can prevent blessing.

Can another sin (not missing faith) prevent blessing? It cannot because we are children of Abraham by faith, not by our good deeds. But every sin steems of unbelieving. So even as another sin cannot stip us of blessing, this sin and the curse have one the same common root, unbelieving.