Two quick reactions to platforms:
1) the available platform support points should just be called , say, "Orbital capacity". Sins called it Logistics Slots, but you already have platform module slots.
2) I advise using autobuild over blueprints. Specify a target size and role(s), and allow an unoptimised algorithm to fill out the platform for players to modify later. As a comparison, as ridiculously shit Stellaris sector AI was, people like me choose to use it because we have more than 5 planets to manage.* This is precisely because Sim city stops being fun the moment one has to decide what modules some backwater station #7 will build. The obvious answer to an average person would be "We don't care, just fill it with economy and a bit of hull", so it doesn't make sense to force them to play Farmville.
Edit: 5 is one of Stellaris's wise decisions on max number of systems players are allowed to OCD over.