The perfect solution would be, once I created a section, to be able to save the whole section (e.g. as content block) to be reused in other emails.

Currently Content Blocks can only be placed inside a column.

I want to create a section-content-block (e.g. call to action with red background) that has no paddings. At them moment the users have to add a section before they can add the content block and then they have to manually remove the padding from the column and the section.