It is an effective PD that gets out in front of a case like this. "Packaging" up cases like this can reduce the misery and the total penalty.
We do not have a client/attorney relationship until you make an appointment, we discuss your case face to face, I accept a retainer, and we explictly agree to enter into representation.
Absolutely. In fact, to the extent that a case is negotiated in advance of the actual filing, it lessens the amount of work that a prosecutor has to do and serves as an incentive for them to resolve the case.
Yes. Sometimes this is exactly what you want to do in order to get the issue out in the open and see if it can be figured out early. Maybe changed from Superior Court and filed in District Court for example.