Hello,
1- Sorry to say but right now, under the Dashboard > Theme Settings > Typography > there isn’t a specific Letter Spacing option available right now. The Sections or Elements which are made through Page Builder plugins, there you can be able to add Letter Spacing through options available (if applicable).
Although, you can mention where exactly you want to add Letter Spacing so that we can provide you the CSS for that. Through CSS you can easily add Letter Spacing too.
2- To configure the Buttons formatting, you can go to Dashboard > Theme Settings > Styles and colors > Buttons > there you can configure the options related to Buttons: https://xtemos.com/wp-content/uploads/2020/09/buttons-wd-7.jpg
Can you please specifically mention through an Image or Video which Border Color are you referring to that you want to change Color of?
3- Under the Single Product Layout Builder of the Theme, there is specifically a Short Description which you can make use of: https://ibb.co/2hsLwfP
For the Description under the Single Product Layout Builder > the thing is it is coming through the Product Tabs element > which adds all the default 3 WooCommerce Tabs i.e. Description, Reviews, and Additional Information: https://ibb.co/kKCdmJm
For the Description, there isn’t a separate Widget available, unfortunately.
Best Regards.