re: Colonization of low-earth orbit
We can't colonize anything if we can't keep more than 3 people in low earth-orbit. Extra safety systems would be needed for a skyhook orbiting venus, above and beyond what would be needed for earth. A failed rendezvous would be certain death, without a powered means of reaching the nearest aerostat landing facility. I'm not saying it couldn't, or won't, be done. I just think that is a decision for future generations, for whom we can hopefully build a series of colonies in earth-orbit, and who will be more familiar with the challenges of living sustainably in a space colony.