Lawyer recommendation to help with exercising stock options?

I know this is slightly off topic as these are questions from the W2 perspective. I am curious if anyone has a lawyer with experience in the realm of exercising stock options? Specifically, I'm wondering the following:
#1 I'd like to confirm that the business has the right to execute a valuation of the business at any time. (A valuation was completed in###-###-#### This decision will negatively impact my in the money options substantially.
#2 How long does the business have to make the decision to either issue stock certificates or buy back the options? I'm being told if I write the check today to exercise, they will hold my money until the valuation is completed. They think end of Q1
#3 The corporate lawyer said they would be willing to only start my 90 day counter (per contract) once the valuation is done. However, this offer was only made in email. The options offering is very clear I have 90 days and I am 30 days in already, going back and forth with him.