My question involves criminal law for the state of: Pennsylvania
First Backstory: Back in 2010, I met this young woman (to protect her: Her name is Sandy) and she had a little sister who was 12 at the time (Lets call her Candy, she's been 18 from when I met her). I've been friends with both and I know my rights and Candy's rights. I know that it's NOT illegal to talk to a child, as long as it's not anything of an adult nature (I.E. Sex, Drugs, Alcohol, etc.) and I never crossed that line. Candy & Sandy are half sisters or adoptive sisters (can't remember which ATM), and Candy's dad is an excon with prior history of assault. I've never met the guy. Never cared to. Only heard from the sisters & mother that Jean (fake name for Candy's dad) is WAY over protective of his family and borderline psychopath. I've never had sexual contact with either girl, at any age (I'm not into kids and as even as an adult, I've known her as a kid, it's just weird to think of her sexually), honestly I haven't seen either young woman in person in around 5 years.
Why was I friends with an 18 year old and her 12/13 year old sister? We use to play Magic: The Gathering & Yu-Gi-Oh! at a local card shop. We also enjoyed the same animes, memes and music. So we had things in common we could talk about and build a friendship over. Now I've NEVER been to Candy's house. I ONLY walked her to the base of her street to ensure she got home safely (if someone grabbed her, I could run over and intervene) as she was a minor as her sister and my (ex) friend were having couple time and wanted her to get home safely. I have NOT been to her house since. I do NOT remember her address. I have NOT been in her house after trying to help her fill out an application & resume in 2012.
Let's skip ahead a bit to today. So after talking with Candy's mom, her husband apparently logged onto her Facebook and read our messages. Now, I'm not coming after any of them sexually. However, I know Jean is a hot head but being a excon gives me reason to believe there's iron in his words. To more or less extent, he said he's never liked the fact I was friends with his daughter at any age and threatened to beat me to death with a lead pipe (word for word, I can screen shot this if needed, just gotta figure out how I take out the parts of names as I wish to protect everyone, including the guilty party as I do not want to disclose their name publicly) and said that if he believes he's lying to ask around his neck of the woods. And he'll only act on his words if his stepdaughter gets as much as a headache from me.
Now, being friends with her for a little more than half a decade, along with her sister & mom, I'd like to think that if Candy didn't want me contacting her any more, she'd tell me or block me. She does communicate with me once in a while, she's busy school & motherhood, but I'd like to think she'd tell me "Hey Luke, I don't feel comfortable with you talking to me. Would you please stop contacting me?" Or at the VERY least her mother or big sister would tell me. She knows I've been told that before and I've been VERY respectful.
I've checked online and I have seen it is a offense, but I want to know if I should act on it or if there's any grounds for a restraining order. I haven't contacted police yet out of respect for Candy, Sandy and Candy's mom as I know threatening to beat me to death with a lead pipe is definitely looking very bad for an excon with a history of violence. I told Sandy to relay the message to Candy & her mom, as long as he doesn't message me with violence again and doesn't approach me with hostility, I will NOT seek action. But in the event that I must escalate to legal action, I'd like to know my options here. I do own a machete and I do own a sword, I'd like to avoid using those.

