One cease and desist letter from an attorney should be enough to get them to leave you alone. Just one letter. It need not become any more of a 'legal matter' than that. It may be worth it, in the long run, to keep from being DFed and shunned.
I agree with this. If you find a kindly lawyer (they do exist), the fee needed would be well worth it.
I think moving homes will definitely help with getting rid of their ability to contact me. I will definitely take your advice on going through the post office to pick up mail.
Forget the post office. Get off of the grid. Get your bank statements and bills electronically. Use a friend's address in another town (than your new one) for driver's license and healthcare info (if applicable). Get a new phone number and do not give out your address, phone, or work to Mom. Create a throwaway email to stay in touch with Mom, but close it within a number hours, or else just message via a Mom-only facebook account.