is it possible to ‘white label’ a commercial Theme, so that the theme panel in the dashboard doesn’t show the theme branding and/or can have own own brand/company name.
And also the theme names in the html/css/js source code would be replaced with a name of choice (ex.: company name, domain name).
Yeah, technically it's possible. I can see the following scenario: the user installs the theme, after he activates it he is asked the company name and any data needed. Then this data is used to update the existing default data in theme files and database and voila, he gets the theme with data he provided. (or it can be fetched from the site name and domain name, of course)
You just need to buy a theme for WordPress and configure it for your self with any domain or company name you need.