Well, I don`t have any problems with JTACs which I create in my missions. So I can`t help you with hints or advices, but the point where jtac does not ask for a special weapon is not new.
The voice recordings for the jtac have been made a "long" time ago. And now as we have got some new weapons (radar guided rockets etc.) there is no recording for them.
As you wrote, he sometimes only says "use ...".
The same "problem" we have for the gulf map. Airfield name recordings do simply not exist.
I`m sure others will help you finding a solution for your other questions.