Poll formatting is very limited and can only be changed by means of CSS. Even so, it is difficult to figure out which classes to write CSS for.
1. Questions are formatted with H2. This is wrong. Just because the only hierarchical level currently above the question is the page title does not make a question a header!
2. H* formats should be reserved for real headers, such as section headers (see https://forums.wildapricot.com/forums/308932-wishlist/suggestions/42891228-support-dividing-questions-into-sections-in-polls).
Possible solutions:
1. Provide a rich-text editable template as is done for some other forms, like invoices, where one can apply standard formatting for all polls.
2. Provide on-the-fly editing before publication, as is possible for most e-mails.