I don't think it's spoiling anything if the game designers intended you to know it.
Something you should know: Max population is not just based on the size, but on the type of planet. Thus why Nixitos II has a lower max then Yian II.
Pelenor I has a current max population of 3. So Terraforming and Bio spheres are a must to get it to be worth anything. Though it's still quite useless after that due to the still very low max population. I've got no idea what I would use it for.
Yian II is a very good planet to settle despite being mineral poor. So settling there should be top priority. Nixitos II is a no-go planet in my opinion. Ultra poor="THIS PLANET IS BAR NONE WORTHLESS" to me.
Freighters are important. They carry colonists and food around. They make building new colonies much easier.
The farm is not exactly a good option. Since food becomes very easy to produce later in. Biospheres are not that good either for just the +2 to max population, though it's better than the farm.