Quote Quoting epochone
Questions: 1) Since California recognized the Ukrainian marriage, why would it not recognize the divorce?
First, you state you petitioned for an annulment, not a divorce. Beyond that, there are issues of public policy and residency - your wife apparently is a resident of California now, not the Ukraine, and thus she can object to an effort to annul her marriage in her former place of residence.

Quote Quoting epochone
2) Her Immigration status is up for review in a year; do I have any chance of causing the denial of her lawful residency in the USA?
Any statement you give would certainly be considered. If the USCIS accepts your account, they would certainly have cause to question whether she should be granted residency.

Quote Quoting epochone
3) Will USCIS wait until the 2-year interview before doing anything with the case? Thanks in advance.
At present, they probably don't have any information which would lead them to take sooner action.