Somebody got them all?! I enjoyed this one in particular because, even though you had to start with "C", there was more than one possible path to get em all. :)
Great! Not too sure about 'half of K', after seeing the answer I assumed you mean the 'right' half and not half of 2 like I thought. What about calling it 'headless K' or something like that?
Yes, the capital letter in these clues always refers to the complete answer associated with that letter (unless otherwise specified). So 'half of K' means half of 'K2', not half of 2.