> Why is the moon at the right distance to provide a gentle tide, and exert a stabilizing effect on earth's axis of rotation, thus protecting life here?

A possible answer to this stems from the anthropic principle. We evolved in a place with a moon because the moon helped us evolve. We don't see no moon because complex life such as us would not have developed without it. A stable rotation and gentle tide are conducive to the evolution of complex organisms; tides were instrumental in getting life out of the seas and onto land.

"Why is the sun the way it is?" can be answered similarly. A smaller star has too small a habitable zone where liquid water can exist. A larger star would have burned out sooner than the 4.5 billion years it took to develop sapient life. A double star has a much smaller set of stable planetary orbits. That the sun is an appropriate star for our life on earth is not divine providence or an enormously unlikely coincidence; it's the result of a universe-wide scenario of statistical multiple endpoints.