Some ideas:
Positive:
1. I have reviewed the documents and I confirm that everything is correct.
Negative:
2. I have concerns about this statement/section/stipulation/clause/item...
2a. ... could you please explain this statement to me? Or, can you please clarify this statement?
2b. ... can you please confirm that this statement is true/valid?
2c. Everything seems to be in order except ...
2d. ... was this statement written in error?
2e. May I propose the following changes/modifications? ...
2f. I believe there may be an error in this statement, ..., can you please confirm that this is correct?
2g. Unfortunately, I cannot sign off on this contract as written, please adjust/clarify ...