The first one is expected. The “Style” group affects the wrapper of the submit button. This has technical needs. So to style your submit button, use the “Style” group in the “Content” tab. You should find all needed controls there.
The second one is a bug with the new “Loading Icon” control, which I unfortunately cannot reproduce. The custom loading icon should just replace the source, but not the behavior of the Bricks default loading icon. Can you find some CSS causing this?