It don't think it does, at least not completely. We know space dust gets through - hance the need for deflectors. And in Divergence, we see a part of Enterprise brak off at warp - the grappler - and it immediately slows down and falls behind the ship, despite still being in the warpfield.The issue is whether or not the 'warp field' mitigates the interaction between the ship inside the field and the outer space-time continuum or not. If it doesn't, then what you described above is o-kay. If, however it does, then it could just have been a vibration/stress issue.
It's also the explanation given for the aerodynamic shape of Federation ships - to reduce the "drag" while at warp.