Is my attorney being thorough or is it that he doesn't have a clue?:
He is doing exactly as he should.  

These cases can cost a firm a fortune to pursue and he needs to make sure that taking this case on is a good financial decision, meaning that not only is it a good case that they can reasonably expect to win on but also that the recovery involved will be sufficient to justify the time and expense involved in taking it on.

He can't do that without an informed opinion on the facts involved.

What more are you expecting him to tell you?  He will either agree to represent you or decline based upon the others opinion weighed against his risk factors.  And even if he declines to represent you, it doesn't necessarily mean that your case isn't worth pursuing in general.  It just means that it isn't worth it to him.  If he feels you have no case period, he will tell you that also.