I spent about two hours trying to figure out how to create my own, personalized keyboard shortcuts. Specifically I was looking for a shortcut that would allow me to open a compose message box for mighty text. I looked in to tasker and everything such.
FINALLY, I found something. An app called Anycut allows you to access and run activities. Specifically, one activity is important. It's a settings activity called Quick Launch. Looking at the various settings activity, you may find two activities called quick launch. Use the first one. After opening it, you should see an app that looks something like this.
When you run this app, simply select a line and it will allow you to create add a shortcut. You can override old shortcuts as well. In the top right menu button, you can also select to create shortcuts for activities.
It's supposed to work for stock and I know it works for aosp. Works on PACman for me anyway.
I think it's pretty useful and hopefully this will help someone if they have trouble finding out how to create personal shortcuts as well.