Usually a pratical way to play, without a board (seeing patients this moment will retire to play shortly)If qb8 can force this line it could be a good weapon, will check tonight mikhail any ideas???

Golubev mentions this in "Experts vs. the Sicilian" - 16. Qa5! is indeed the way to deal with this line. It gives the knight the option of going to c5 when it's kicked with ...f5, and it also prevents the queen from coming down to b4, thus giving White time to play Bc4-b3 (oh, and as you say, it deals with the threat of ...Bh6).

This looks nice for black in the line you gave if white is tempted to play 17.Bc4?  Then, 17...f5! 18.Ng5 e4 19.Bb3 Qf6 20.c3 Rxb3! 21.ab3 e3! looks like a win for black.  But, if white sees that coming and plays 17.Qa5 instead, he still gets hammered with something like 17...f5 18.Ng5 Rxb2+! 19.Kxb2 e4+ 20.Kb3 Qf6 21.c3 Qxg5.  Pretty good stuff.  17.b3 looks crazy, but it may be white's best defense.  Black can try using 17...a5 with the idea of a4 as a can opener to bust open white's king position, but white casually ignores that with 18.g4 a4 19.g5.  For example, 19...Qa3 20.Qc1, and white will soon play Bc4 with advantage.  This is why I prefer simplicty when I have 12.Bd4 played against me.  I just trade off with 12...Bxd4 13.Qxd4 Qb6.  This works well, and white usually loses.