Your fiance should discuss this with his lawyer. If he is not satisfied with how his lawyer is handling his case he can request a new lawyer. This may delay things a bit, but better to have someone he has confidence in.
The usual order of things is that you post some collateral to the bondsman and he posts bail and the defendent is free pending his next hearing. Usually the bondsman will not come after the collateral until the defendant has missed this hearing and the court puts out a warrant. However, the attorney that said look at the agreement may be right. If the bondsman knows that your friend has left town and is not planning coming back there may be something in the agreement for him to collect the...
Someone needs to testify to this information if the defendant themselves does not testify which in many cases they don't. Having someone else putting this information on the record is difficult as it is not generally considered relevant to the charges. Discuss this with your lawyer as their experience will be the best guide for you.
You are doing drug court to presumbably avoid a felony conviction which will always be on your record as there is no expungement in New York State. Speak with your attorney about the pros and cons of continuing with drug court or taking it to trial. They know all the facts of your case and can give you advice on which way will work best for you.
A passenger cannot be charged with DUI for the simple reason thta he wasn't driving. Were you charged with something else like public intoxication? You definitely need to get an attorney to straighten this one out for you. Good luck.