Although there is nothing wrong with the clearance you received I do think you have a point.
I wouldnt go as far to say that the clearance is unsafe and if it was too much information you were correct in asking for confirmation however, as a controller, I wouldnt usually give such a clearance. I would rather, depending on workload, wait until I observe you passing 4,000 and then give you the heading to make sure there was no mistake.
I don't advocate my way being the best but I used to fly commercially and do remember the high workload during the initial climbout and giving too many numbers in that initial departure instruction could cause mistakes. Whenever I am training a new controller I INSIST they do it that way initially......too many times the pilot will come back with questions the other way.
We are taught, as controllers, to combine transmissions as much as safely possible without giving too many numbers in each transmission. The clearance you received definately falls into what is considered acceptable by ATC but like I said..........may not be prudent during that time of flight.