The first part is fine, ships are indeed destroyed if they enter, but you can fly past.Any ships who enter this system without passing through on the same turn are destroyed, and all colonies within are reduced to Outpost status, with a max population of one tenth. Furthermore, it is impossible for anyone outside a system containing this building to see into it.
A dimensional tear capable of magnifying the destructive potential of the Void Mind in a localized region.
For the second, while the population is reduced eventually to 0.1, the planets do not become outposts. They are just populated planets with very tiny populations. So that means you can't build a colony there, although that might make sense as how would you move people and materials there?
However, you can build other things like Outpost Bases or Troop Drops that aren't available to outposts. Further, the planet with the ship facilities is still able to build ships and even upgrade those facilities. If you do build a ship, it isn't destroyed if you move it out of the system the turn it is constructed.
Is that the intended behavior?