I'm definitely with y'all about the food comps -- I always really enjoyed the ones about playing for specific items/food categories or food for different days of the week for the house. Mixing it up as not just being about have/have-nots and doing things that make the whole house play together for food can be more fun. Just keeping it different every week.
And more luxury comps! Make them work for things in the house, give them goals and new things to be excited about. I actually kinda miss America's Choice for things other than have/have not situations, since America's Choice-given luxuries tend to also freak out the HGs a little in regards to what America thinks of them, and it does make them excited when America decides they get that phone call from home.
Definitely a more diverse cast, but that's a given. Some of the more intriguing and likable characters in BB history weren't the typical casting.
I actually really like the 'give them games' idea mentioned earlier, but heck, even toss in some board games. Rotate in some card/board games every now and then to at least give them something to do. Nothing like a horrible fight erupting over Jenga or Apples to Apples.
And they really, really need to mix up the competitions. They're just too predictable. And I think even just surprising them with different formats -- a competition that extends throughout the day as a series of little things or mini-scavenger hunts for the veto, luxury comps sprung without any prior warning, ongoing hidden clues throughout the season in the house that can be shared with others or hidden by the finder...
I actually like the seasons with multiple alliances and layered groups and backstabbing because the groups that are all about the social game and the nicey-nice... well, they're kinda boring. You get groups like this season where everyone is so terrified to make the big move, to do ANYTHING useful to shake up the house, that it gets ridiculous. It's funny that this was the most BB-aware and educated house ever, yet they couldn't use that knowledge of past strategy to even see simple things under their noses. Divisions and alliances create better drama, like the Sov 6 v Nerd Herd where you had genuine stakes every week with the HOH and there was a real sense of tension for every competition. Not just everyone throwing it because they don't want to get their hands dirty. People in the house who know it's a competition and not just living in a hosue being social are what give us the classic moments, they give us convincing Marcellas not to use the veto, they give us Janelle's constant comp success, Dr Will's very awesome existence. I want to see people who are willing to win HOH and make the tough choices, whether smart or stupid.