Name a ship that was damaged by a V2 or a unit that was delayed on its way to the front by one.
The Nazis would have had to launch hundreds of them to have the effect of a single Allied bomber raid, and they would have landed randomly across a target area miles in diameter. Also, the Allies were never presented with a similar target. A V2 type weapon would have been useless to them. It was almost useless for the Nazis.
JATO units are nice, but they were scarcely a vital part of our national security plan. Mostly the USAF and USN were interested in getting fully loaded bombers off as quickly possible before the bombs (from ICBMs) started landing. The strain on airframes was so great that they seldom used today...
I wasn't attempting to make the point that the V2 had any military utility beyond it's potential to carry an atomic warhead. Even then, the early A-bombs would likely have been too heavy for missile delivery. Not to mention that the failure rate of early ballistic missiles would have made a hypothetical nuke launch very hazardous for the attacker.
General Eisenhauer himself said that D-Day could NOT have succeeded if the German V2 rockets had been ready to attack the English ports and the Normandy beachheads in mass.
But I guess you know more about this than General Eisenhauer.
Here are some links, if you wish to educate yourself.
http://www.constable.ca/v2.htm
http://p208.ezboard.com/ftalkinghistoryfrm8.showMessage?topicID=182.topic
http://www.leesaunders.com/html/SWeapons.htm
http://www.historylearningsite.co.uk/v_weapons.htm
Note the built-in JATO units just forward of the USAF insignia on the fuselage. Incidentally, this is a B-47A, so the incorporation of JATO must have been part of the basic design criteria for the B-47 Stratojet. I think that they wouldn't integrated JATO into the basic airframe if it was as much of a problem as you said it was. Probably had more to do with the relative lack of thrust that you could develop on the early turbojets.