How to Create Child Theme with Existing Genesis Premium Settings

Thanks @David.

I feel that creating a child theme is more of a headache, then using the existing theme.

So I prefer to store my functions.php file whenever I make changes.
And then copy to the new version of GP theme.

I will use Additional CSS for my requirements. I hope that stays the same without any changes.
Even if it changes, I would like to copy that code and save it and copy again.

This way it looks more simple for me.

It really is not that difficult and is worth spending 20 minutes making it work - the problem you may have is that WP auto updates themes now - wouldn't want to risk losing your changes if that happened....