I (F27) have an opportunity to get a good job after a year of searching but my abusive ex (27MtF) works there. How can I safely go about this?

TW: sexual abuse, sexual corercion, stalking, potential attempted kidnapping, mentions of other abuse.

About 7 years ago, my ex (at the time male, yes it is important, will use she/her to be respectful to her gender) was getting very controlling. She dropped out of college and wanted me to text her all the time. She hated that I joined a student club on campus and had friends outside of people she "approved" of. At the time, she was corercing me into sleeping with her or doing oral on her every time I saw her (a class E felony in my state) because she felt that I "owed" it to her for being my partner. She also was becoming financially abusive as well. Eventually, I knew I needed to leave during what was in my mind our "last chance" date.

During the "last chance" date, I didn't tell her what it was because I knew she would love bomb me. We went to her place, which was a biohazard level mess, due to a dog using the bathroom on the floors inside. She coerced me into having sex with her by quilting me and arguing with me about "how much she does" and that I "owe" her. So I did it, and I was unsatisfied and felt used. At the end of it, she was telling me she wanted to see me pregnant and was suggesting she wanted to cum inside of me unprotected to do so. I thankfully shut that down, but there was a look on her face and some body language that felt like she was deciding if she wanted to ignore my "no." We went into her game room, and she wanted me to watch her play a free to play porn game on her gaming PC. I didn't want to do that. Instead, I started to play with Snapchat and sent silly filter selfies to the group chat of my college club friends. She REALLY didn't like that. She grabbed me by the back of my head, got in my face, and said, "I can be as much of a boyfriend as you want me to be. That's up to you." Something possessed me to make her say it again, and I hit record on Snapchat. She did it again and said it again. I made sure the camera could see me trying to pull my head away and could see both of our faces. She saw me record it and had me delete it. So I backed out of the video... but Snapchat saves all video regardless of if you send it or not, and she seemed not to know about that quirk.

Cut to a week later, and I moved in with a male friend (now boyfriend of almost as much time since the breakup) so that if my ex got into our building, she wouldn't be able to find me (or break in because I lived on the ground floor). I broke up with her, and I thought I was safe because she lived about an hour away. Turns out... I was kind of right to be. She kept trying to make me meet her alone. Like she would actually get mad if I said I even told my friends about her wanting to meet me so they can check on me after. She then suggested I get into her car to "drive and talk" to get my things back, and I gave a hard no. Finally, on the next day I knew she had off of work, a male matching her description down to the unique jacket she had at the time was seen at my main college class building from open (6 AM) to 2 hours past closed (2 AM) and it was freaking people out enough that campus security sent out a warning and tried looking for that individual. The only discrepancy between them was she was 20, and the guy was described to be in their 30s, but my ex really let herself go in many ways from fast food every day to not even doing basic hygiene that my college friends saw pictures of her and were shocked she was 20 not 30. I truly believed she wanted to kidnap me and potentially rape me to baby trap me. She also tried to lie to people, claiming I had a mental breakdown and cheated on her (I did not).

So it's been 7-ish years since the incident, and a relative of mine might have a great job opening for me. They work in upper management and will be a reference for me and my partner, we both will get about $5 above min wage, a raise after a year, full insurance coverage, retirement, and other benefits... but it's the place I know my ex-girlfriend (formerly ex-boyfriend) works. My family doesn't know what happened to me because they are heavily conservative to the point where I can't be 100% that they won't blame ME for what happened or won't tell family that would blame me for what my ex did to me.

I plan to apply for the job, so I need to know the following:

1. What's a good safety plan?

2. Even though the building is large and we would be different departments, there is still a chance we might see each other. What should I do if I saw her?

3. What do I do if she tries to talk to me?

4. What should I do if she tries to talk to my partner?

5. At what point do I tell HR about what happened?

6. At what point would I show HR the video of her grabbing my head and getting in my face?