Slop came into play during Season 7 - All Stars.   Before that it was PB&J.  Season 6 was the first season with the current house.  Before that the HOH room was tiny, small! 
I've been revisiting previous seasons of BB.  I did not like Season 1 for various reasons, and think all of the changes have been for the better.  I don't want to vote on the houseguests or who to nominate.  I've started to dislike American Idol for that very reason, because its a popularity contest and not a skills contest necessarily.  
The reality is that BB still kills it in ratings during the summer so I don't think they'll be changing anything anytime soon. 
I would love to see the challenges mixed up a lot more.  I don't like that the houseguests can predict the competitions.  I think they could use some more originality in that respect.   
I also think that production should stay out of the mix as much as possible.  Quit planting ideas, quit giving hints.   
Retire OTEV.   Seriously.   
And, I like the magician idea, but I think a pyschic would be better.  Can you imagine what that person would know ahead of time?   Heeheehee . . . .   that might really screw with the houseguests.