what you're saying is echoed by most. There is evidence that NASA blacked out photos. Some of that just may be enhancement, the same way models are glossed up on magazine. you would think you wouldn't gloss up data, but maybe that's all it is.
but to the point it would insane for aliens to build things on the moon? Well, no- not if they wanted a base here but recognized human sovereignty. A moon base would quite reasonable, and within their means. If they came here before life was on earth, for the purposes of terraforming earth, you would want to moon base as an operation platform to watch the progress from safety.
thank you for writing, Ray.