My guy could just kill and do horrible things to innocent people but that would be too easy and turn all of the 'victims' into criminals.
Also pretty sure that merchant got the bear for 90% off.

And we have confirmed that Marie wants to be more than just a maid.
She for sure does. Lets be clear she was ready to be used sexually right from the start, the emphasized ready to do anything line carries that meaning rather explicitly. So she was ready to endure that out the gate, but now she clearly would enjoy it.
This is also kid of one of the problems with series like this, the self censoring of manga stories as well as the actual censorship from publishers. If he wants to be a evil noble, why is he not just indulging. Him "forcing" himself on her would make sense if he is trying to be a evil noble, and it would also entirely backfire as she clearly would welcome him. But age rating limit that as well as the very tiresome keep all characters virgins plague.
But on the topic of the premise not fully working, he has no reason at all to want to be the villain anymore, his goal was to survive being a mob that is killed early, and being the final boss and defeating the hero was his long shot idea, that is clearly no longer needed.