Ok,I edited the custom planets.xml and more importantly ,the planets configurations,both files can be found in the Data folder (and also in the Metaverse for internet ) ,in order to ensure at least class 1 for all planet types(all the upper limits remained constant)
For the standard galaxy map,Earth and Altaria are now class 26,as well as all homeworlds.
These changes are made to address the very slow research rate on first campaign scenarios.
Also,the galaxy now "feels" like a huge space populated with stars,planets and resources in the sandbox game;use abundant settings for a massive play experience.
Just find the apropriate files,back them up and overide them with those in the archive
Have fun.