Yes!
Great idea! How it didn't occurred to me before?
I'll erase the Ice and Gas planets with Oxigen to simulate that Rock people need Domes in those planets. Since I always play Rock/Oxigen it'll be perfect.
Humm, I have to check first that none of the existing races is Ice or Gas/Oxigen..........
And as a side effect any AI race that is "Rock/ none Oxigen" will still capable of fully colonizing Ice and Gas as a bonus.