I am sorry to hear of your difficult situation and am working on your answer now.
Mediation is normally much less expensive and often more effective than forcing the matter to trial. In addition, courts typically grant motions to compel mediation so even if you refuse to mediate, opposing counsel can request an order from the court and you would be forced to mediate.
Therefore, it is usually a positive step and now that you have a favorable report, they are more likely to settle the matter since the court would likely rule against them.
The default rule is that each party pays their own costs and fees.
Sometimes a court will order a party to pay a portion of the other's fees though where a successful motion for sanctions has been filed. A motion for sanctions requests the court punish the other party for filing false statements or engaging in other wrongful conduct typically.
NOTE: The law sometimes does not provide the answer we hoped it would. Please consider that I devote time to providing answers whether it benefits you or not and hope you don’t choose to shoot the messenger.
As always, I am available to clarify the answers for you. Thank you and the best of luck.