She sounds like a horrible person! Honestly she seems like a very aggressive person. As far as your USPS mail goes, you should talk to someone IN PERSON at the post office. Go in there and talk to a manager and get their sympathy, stay calm, but express your distress, sugar will get you further than lemons. Tell them that she intercepts your mail and that she opens your mailbox and is fraudulently using your address. Maybe they can help you. Call UPS and FEDEX and ask to talk to a manager, see if they can put some sort of notification under your address. When you get mail or packages that have her name on it, DO NOT give it to her! Cross out your address and write "Return To Sender". And if you're home and UPS/FEDEX try to deliver something of hers to you, tell them that you are REFUSING the package. As far as everything else goes, you need to personally go down to the police station and talk to the sheriff or officers who have not been involved previously. She pulled her pants down in front of your child-that's sexual harassment to a minor! She is breaking so many laws-destruction of property, trespassing, vandalism, harassment, threatening to do harm, attempted assault (her son throwing rocks). Honey, you need to file charges against this woman and show her you're not to be trifled with. Whether you are renting or not, this woman has NO RIGHT to do these things to you! When you talk to the police, bring proof that you rightfully live at your address, talk to someone who will listen and lend you a sympathetic ear. Also you need to start taking pictures of everything that woman is doing or has done if possible. If the police and post office refuse to do anything, then you absolutely need to talk to a lawyer, many of them will do free consultations.A call from a lawyer might put a fire under the local police and "inspire" them to enforce the law properly.