Hello, many thanks for so detailed issue. I fixed most of the bugs you mentioned about the F12 key.
Now this pluing try to call the browser directy instead of using "webbrowser" module.
If the browser is not found, please post the path to the browser here, I'll be happy to add it.
About updating the readme.md file, i added some of the things you mentioned, but please, fork the project and add anything you think is important. Contributions welcome.