The X is not totally take out (cannot be short in C)
3S show the 18-22 hands with great S
4d is 2noQ
4S is asking for K of C (implying stiff H or the K of H in opener)
4nt = no
5H asking for extras (bypassing K of D,QH,) wich is likely to be the QD as the Qc would have dubious values.
5S = no
responder showing 2 keycards over a 18-22 make 4S an asking bid not a signoff.
Note that over the X opener is very well placed no matter what hes got. (Hes got an unbalanced hand with 12-14 or 18-22) he will bid 2D/2H/2S with minimum or pass with 4C in the suit, if hes 18-22 hes going to bid 2Nt+ totally GF.
If responder had the Q of D im not sure there is an easy way to find 7.