One thing I would add is slip of high heels

No use in trying to run away from a mad man if you fall over and break your neck in the process

My alarm which is pretty high tech will actually ring / send a text to several nominated numbers to let them know that the alarm has gone off

I also have 2 alarm boxes one outside ( standard) and one inside this makes the noise of the alarm going off incredibly loud as it's in a confined space it's literally ear splitting  no way would anyone want to stay in my flat / house with it going off it's evil

You can have alarm equipment installed which is removeable should you need to move. I had a contract but found the system very unreliable and flimsy. It actually failed on me without the company notifying me. I eventually switched to stand-alone supplied by a local firm which required more initial outlay but much lower maintenance costs, and the system is a lot more sophisticated, reliable (it has more than one way of relaying a message if activated), and robust.

I wish I'd taken this up earlier instead of messing around with an anonymous company thinking I'd gotten a good deal.

A spy hole, chain, proper window locks and someone who knows when you are working and when to expect you to phone in are also what I'd consider essential. The person doesn't have to come around or even be in the same area, they do however need to know when to phone the police.