Ok, thank you for that information.
Based on the fact that you mention he "pled" guilty to an offense without a hearing, and based on the limited information available, it appears that this new arraignment is for a separate, unrelated offense.
If this is indeed the case, then the prior offense (which he pled guilty too) cannot be attacked (absent a few circumstances). This is because when someone pleads guilty to an offense, they are agreeing to give up any right to trial on that offense (which is the only way a Court can hear all sides of the case). In fact, the Courts, prior to accepting a guilty plea, always engage in discussion with a defendant to ensure that he/she understands what he/she are giving up in exchange for a guilty plea (these usually include the right to have a trial, the right to testify on your own behalf and the right to present evidence and witness testimony on your behalf).
On rare occasions, a defendant may be able to request that the plea be vacated if it is based coercion or fraud. However, this request must be made within a certain time frame after the plea of guilty (usually 30 days). Once this passes, or if no evidence of such fraud or coercion exists, the plea cannot be vacated.
On the other hand, if the "waiving" of this hearing is related to this new offense (for which he will be arraigned on), then I can only presume that the "hearing" you are referring to is the preliminary hearing. A preliminary hearing is a hearing that occurs before the arraignment. At a preliminary hearing, the only issue the judge has to determine is whether or not there is probable cause that a crime has been committed and the defendant was the one who committed the crime.
The standard of proof is probable cause (and is different from what has to be presented at trial, which is proof beyond a reasonable doubt). Evidence of the "victims" past transgressions are/may be relevant only at trial (which occurs after a preliminary hearing and after an arraignment) and the victims transgressions are not relevant during a preliminary hearing.
I will pause here and allow you to ask any questions you may have.
Regarding phone calls, they would be an additional fee (as a part of the "premium service" offered).