Make a custom theme for mailpoet3

The project consists in building a custom theme and changing the way mailpoet imports products from the website. Mailpoet allows to insert content directly in the newsletter but he doesn't do it like I want to, here is a description of what I need: - remove languages, just pt, it is posting content in all languages, it should just be PT or the language backoffice is in. Translation plugin is qtranslatex; - it is stripping headings on description text and it should leave them or apply a different style to those titles; - insert the wash symbols: symbols on the description that aren't showing on the newsletter content; - insert product color variations - insert secondary images - insert parent and child categories and display the content in a certain way - according to the theme.