Gummi ship- power levels? 100 blocks?

There is still one thing I don't understand about gummi ships. I understand that in order to build more, bigger, and better gummi ships you have to upgrade the computer and such. I currently have the lvl 3 upgrade so acording to it I can- create and save 8 ships, and I guess build ships that are up to 100 blocks? however it will not let me built ships that are under 100 blocks because it says "the ship is too big to build" Is it because my contruction area is not big enough I guess?

I'm guessing that I'm probably right on what I think above but can someone please tell me what "power level" has to do with the ships?

You don't have enough blocks most likely...
And power level is how much shot thingies they use (the blue mp like meter)

comp lvl 3 lets you build ships up to 200 blocks. I don't think you need to upgrade the area because 6 cubed=216. Plenty. But might as well.