No. You are taking an extremely superficial view of the problems and claiming that we know the solutions. If you take your points together then they claim that we can build a viable closed eco-system. The experiments that have been conducted so far show that we cannot. We still do not know how to engineer a closed-loop that can survive for more than a few months and every experiment so far has had to shut down or risk killing the participants.
Sure we know how to build bunkers - do we know how to do large scale construction in a hard vacuum? Can we build a fission reactor large enough for a small city, launch it by rocket and land it on another orbital body? Or is it so easy to assemble it over there using our well-developed space construction skills?
It must be some utopian blend of crack in that pipe that you are smoking. Nobody is claiming that we can't learn how to do these things given the will and the experience, but to claim that they are already solved problems is just ridiculous.