aye, you have good points.
this kinda falls back in to the other discussion, the random fun stuff in space. I generally picture it something like a tree;
You have the main trunk, maybe two or three of these, one for every two factions, at one end you have branches, at the other end you have roots.. which essentially are the same thing.
The main trunk, everyone knows the routs, the names of every planet on them, the name of every system and the inhabitants. Then you get to the branches, each grouping of branches would be part of a separate set of exploration. One faction or another, expanding outwards, exploring, colonizing, setting up way stations.
Then you have the twigs and other odd bits of space junk. Systems with no value, little value, or unexplored.. connected here or there to any number of places. But no one has maps to them, or if they do, its pirate controlled maps, hidden illicit stations and the like.
the main trunks would all be quite survivable, but branches from the main trade lanes could have jumps that go through highly ionized nebulas, or jump past stars with extreme radiation.. or debris fields a dozen AU across due to a strange gravitational anomaly in a star system, causing all of the planets, even as far out as saturn equivlant, to fracture from graviational shear..
just fun interesting stuff to make choke points in the galactic landscape.
As the map is now, its just sprawled all over like a tangled spiderweb. Give it contour that makes sense, that the eye can follow until you reach the marking that says 'beyond here there be dragons.' :p