How to use mods for custom maps?

Hi, i enjoying playing this mod but i wanna make the map more realistic so wondering how could i make my customplanet.xml to work together along with custom map i made. Every time i launch the game my home planet lost their planet textures and upclose map as well.

And is there anyway i can increase the map size, becuz this 18x18 sectors isnt big enough for what i am doing here.