I dont really get it... They're all WAY too far away from star centers...

Do you just wait til your culture border expands enough? Or chain Starbases til you get there? O.o

You only need to build one starbase. The resource should fall in the culture zone of your starbase. Build the nescassary improvement, and connet it to your starsystems.

Thought you can only build starbase in your own culture boudary...

no, the whole point of starbases is to build them outside your normal solar systems so you can grab these resources or have bases for ships/missles