The post_content is, well, the content that in classic WordPress is a TinyMCE wysiwyg editor and in new WordPress a Gutenberg block editor, it's not a simple text field.
If you want users to submit content that is simple text rather than rich text, you should probably use a multiline text custom field instead of the post content.
As for changing the order of taxonomy terms in the select dropdowns, there are no such options unfortunately.
Thanks. Since the ordering is one drop down I think I'll drop in some javascript to do that. I added a (please select) choice that is the first choice so I will know if they haven't selected one.
For the text field, going to build out just leaving it and then review (particularly on how the search works for searching custom fields).