Capital prices are being reworked so it is high advisable to move your capital to a tech 2 or tech 1 planet. It is not a homeworld. Just a starting point for your empire.
While I like this approach in theory, if your homeworld isn't a tech1 or tech2 planet, how can you guarantee that there will even be any on the map? Many premade maps are full of asteroids and volcanic as it is, and that could cause an acute credit shortage.
Also, did you change how the taxation rate works? 1000+ credits for an extra 50 population is hardly anything compared to what you can get with tradeports (especially as many planets give trade income bonuses), so this will probably always be ignored.