Satanism stems from an enlightenment era conception of Satan, not the medieval. In the satanic temple’s case they also adopt some of the more classic imagery as a way to push against Christianity when it oversteps its bounds. The more grotesque image of satan eorks perfectly for this as it’s much easier to show the hypocrisy with than any other I’ve encountered.
Side note: as far as i know, god is the only character in the bible that already has, and has promised to again destroy the world. Satan (which translates to the accuser or adversary) has mostly just questioned god and tested peoples faith. So cutting away the popular notions from centuries later actually puts satan in a much more favorable light.
I don’t expect them to argue against him inciting an insurrection. I think they will argue that the office of the president isn’t a civil office of the United States as laid out in the constitution, as has been a common legal argument brought forth as of late. So they will probably have to argue that the rattifiers of the ammendment were so worried about insurrectionists taking over government that they wanted to prevent it, but not enough they thought the presidency should be barred to insurrectionists.