The whole thing about sub-space being damaged by warp travel was brought up and then brushed under the rug. It's worth exploring again, even though it was an unpopular idea as it took away some of the utopianism of the Trek universe. The plot of my fan project (if I ever truly realize it in full) is for the ship to explore an area ringed by subspace rifts similar to the Herakas corridor (although probably not literally that area).