Idiot ball,
Plot Induced Stupidity
Um, no. Hotaru didn't touch anybody and she had a tendency to creep out the rest of her class. They avoided her or teased her from a distance. Unless her limbs made audible noises when they moved, and were relatively close to the size of a normal limb, they would have no reason to suspect she had cybernetic parts at all. If you saw someone who always wore long sleeved shirts and long gloves who had been in an explosion, which are you more likely to think: Cybernetic limbs or burn damage?
We are never shown any life on anything save the Moon that I'm aware of.
It looks more like slavery as practiced in the Roman empire.
I see no suggestion of slavery at any point.
I've seen enough of PGSM to know it was very poorly done, and has very little in common with the anime or manga.
It is poorly done in the same sense that the shows the various Power Rangers are based on are poorly done. They are very well done, but are built around cultural elements such as kabuki theater that we don't share. PGSM is the only one to specifically address life on the other planets beyond the Senshi.
I would expect Pharaoh 90 to by flying there under it's own power since we have no reason to think it could not.
And no reason to think it could. We never see it moving itself under its own power. We see it manipulating itself to send out tendrils and such, and we see that it is able to reverse the portal it is moving through, but it could be the energies of that portal that is moving it.
So, you think Pharaoh 90 had more then enough time to get to another planet if it wanted to.
Again, no. It might have been able to make a last ditch attempt at conquering a place where it had already invested substantial resources, but that does not mean that it had time to locate a new target and start from scratch. There is also the fact that StarS suggests that Earth's tech level is on the low end of the galactic average.
And it never crosses their minds to go somewhere other then Earth?
Unlike youma, which can feed off of the life energy of animals as well as humans(making Beryl once again a poor leader by not having her send youma into the woods to drain animals and plants, even if it was less efficient), pure heart crystals apparently only occur in sapient beings. As a result, any planet that they invaded which had the resources necessary to open their portal would have an indigenous population.
But the Senshi didn't know who he was in the vaguest way.
In the manga, as I recall, Ami comments on his recently becoming famous but that little was known about him because he was also quite reclusive, like any number of scientists.