IMO, most of the questions are not really questions. Be SAYC or 2/1, ♣ should be 5+ in this sequence. I don't think so, especially if they play 2/1. not possible. of course. usually 4, 3 should be the minimum. first of all, 2♦ does not necessarily deny 6+ spades. even if 2♦ denies 6+ spades, 2♠ should show extra strength. 2-3-3-5 is quite possible. 6-card clubs should not be a surprise. With Jx doubleton, I wouldn't raise at this moment. see comments above.