MissyYee,
For myself, I think I'll not rom first and stay apart cause I found it meaningless to rom. And further to it, if rom first means got to stay with such in-laws, I definitely choose not to rom first.
I don't know about the others, but I think its going to be a tough fight to 'change your future-FIL' or to 'put up with all those nonsense comments'. I rather stay away from them and let my bf/hb handle them himself. And also, if your bf is currently not speaking up against such comments from his own father, please do not expect him to speak up after he sign on the rom certificate.
As for standing up for yourself / speaking up against the future FIL because he's rude/unreasonable/shallow/pushy, it may seems so 'right'. But do bear in mind that, this will definitely cause a wedge between you and the in-laws since your in-laws' family have been so 'used-to giving in' to him.