re: Terraforming socialistic?
Yup, for private model you need to give Mars to private entity they pay the cost of improvement and get to sell it back to make a profit. Which means Mars would be off limits until such time as private entity finished it's improvement.
That would suck big time.
But a govt doing the same thing- investing everyone tax dollars for the "improvement", and then govt selling or giving away the property would be even worse.
Another way is one to allow people to own land in exchange for debt of paying for their percentage of the improvement cost. Probably best model, assuming you want to terraform Mars.