Most of what you're looking for is already available on the forums if you search for it.
Since there's too many requests, this is all I'll leave you with:
Code:
/run https://www.youtube.com/watch?v=jnLGWph0VZ0
to open a link in your default browser. Make the script safe to run before putting it on your bot though, otherwise you can make other users have access to your run command.