Yeah, it would be cool to work out something fresh, whilst still staying true to the spirit, feel.
For the lead villain it could be interesting to throw him up against a younger, villainous version of himself (I don't mean a clone lol). In Raiders, Belloq was like a shadowy version of Indy but as an intellectual. He was never a physical match.
I think a charming, though ruthless treasure hunter who could match Indy physically (even perhaps moreso with youth on his side) could be a different twist we haven't seen yet.
You could maybe use the ruskies again or would you go for a different feel?
Fun to imagine.