I don’t think it’s Arthur because the coffin isn’t big enough, and it wouldn’t be Lady Denham because that would leave Tom ruined and I think as he’s such a jolly, optimistic character they wouldn’t end the series with his downfall. I’m sure Sanditon will turn out to be a successful resort.
I think the will that Clara and Edward burned must have been a fake as she would have left it stored with her solicitor, because she knew if any of those 3 found it after her death they’d burn it and quite frankly I can’t see her leaving money to a donkey sanctuary when titles and money are so important to her, she’d want to leave it to family to carry on the name.