3 seconds

[Almost Always Right]

First of all - I have to say that 3 seconds is not in my priorities on the floor, however, during our annual clinic we had an instructor that has interperted this rule a certain way and it appears to differ from the "norm" of our association.
Having that said, here is the sitch: A player enters the lane while dribbling and has their head and shoulders in front of the primary defender, secondary defenders then stop the advancement toward the goal and the offensive player then picks up the dribble. While pivoting to keep "working for the shot", the offensive player does not leave the key. The problem is the ambiguity of the rule. When you read it, you will understand what I mean.
The questions are these:
Do you suspend the 3 second count while the offensive player keeps "working for their shot"?
Could you have a 5 second closely guarded before you have 3 second violation?
The problem I have with the ambiguity is the wording about a shot.
Any ideas? Thanks in advance for your candor.
TR