From what I saw, those with minimal hours prior to getting into flight school did not have a huge advantage as to who got jets, vice who did not. But 6 months ago, there were hardly any navy jet slots (i hear that has changed). Those guys that did have 70+ nss's were the ones who flew for continental or who had enough civilian hours to instruct (or were just plain brilliant), but even of the two guys that flew for the airlines, one got jets, the other got E-6's. Its all about timing, so my theory on it is it certainly can't hurt, just keep in mind that training in the navy and training in the civilian world are very different, so be adaptable.
Also, you will probably get to do IFS when you get to API and that will give you some flight hours, just enough to solo, but it helps.
I chose not to spend my money on lessons, which I don't regret. Yes the learning curve is a bit steeper for those with no flight time, but it all evens out in the long run.
Hope that helps....