It's conceivable Trump will have his 8 by the end of Super Tuesday.
I don't see anybody else getting 8 states.
I think Cruz will get his 8 states, but they might include Guam, Puerto Rico, American Samoa, USVI, Northern Marianas, etc. I also think as some of the also-rans drop out, Trump will have a much harder time winning states. Not many who are supporting any of the other candidates are going to move to Trump.
By the way, SC is not winner-take-all, but a hybrid. The at-large delegates are awarded to the overall winner, but the other delegates go to the winner of each congressional district.
Almost, but not quite. Each of 7 Congressional districts can split, with the winner in each district getting 3 delegates.
Otherwise, you are right, the candidate getting the most votes statewide gets 29 delegates for that, and whatever share of the 21 delegates is obtained by winning congressional districts.