Just about all of the terrain is pointless.

All the different types of cloud and dust are spawned in far too small sizes to matter, and then even if "in the way", they don't offer changes strong enough to really matter - plus any effects they do provide are to all ships inside them, so it doesn't really change the status quo of normal space.

One straight forward change that could be made to these (and something which would actually make sense physics wise) would be for the various dust clouds to block sensors - they shouldn't be able to penetrate (at least not perfectly).