Cait Sith is underrated. As I said earlier, his Instant Death slot ability kills everything, including the Weapons.
As far as I can tell regarding Rocket Town, given the architecture and layout of the town, it wouldn't be all that unbelievable to think Shinra picked a random field (Thousands of miles away from Midgar because... well, because Shinra I guess) to start construction of the rocket, and the town was just developed by the engineers and scientists around the project for convenience's sake.
Summons being a waste of time is like a Final Fantasy staple.
I forget... does the game ever even try to explain where the Black Materia came from, and more importantly how the Cetra knew what it was capable of. It's one of the few loose ends the game doesn't tie to the rest of the plot. I mean, how did Jenova/Sephiroth know it even existed? Sure, he probably "heard" about it while in the Lifestream, but that only further asks if only the Cetra were capable of hearing the planet, what is Jenova?
And, with those criteria, it would be a fun thought exercise to turn the question on it's head and ask, where did the Cetra come from?[/yellow]
From FF Wiki:
Long ago, the Cetra were given two gifts from the Planet: the Black Materia, which had the power to destroy, and the White Materia, which had the power to protect. Being peaceful people, the Cetra embraced the power of the White Materia and rejected the Black, sealing it away by transforming it into a complex, booby-trapped, labyrinthine temple that became known as the Temple of the Ancients. This means these materia were created just like regular ass Materia through Mako concentration. The Cetra had the ability to guide the flow of the Planet's spiritual energy, this being the means by which they were able to cultivate life on the Planet's surface. The Crisis Core Complete Guide states the Cetra are said to have opened up Lifestream veins in the land, working to make the Planet fertile(this is probably why the Planet offered the black and white materia to the Ancients as a thank you of sorts).
(Sephiroth found out about the Black Materia through the Lifestream, the Lifestream contains souls from Ancients who know about the whole White/Black Materia shenanigans and unlike common misconception, the Ancients were actually natives to the Planet but they were a nomad tribe hence why they would be able to hear the cries of the planet , the interstellar travellers were the folk from Spira some time later, the translation made it seem like Cetra were aliens but it actually meant that they travelled the planet like Nomads, According to Sephiroth, regular humans were Cetra who forsook their migratory nature to form permanent settlements millennia ago. See http://finalfantasy.wikia.com/wiki/Cetra
for more info on the Cetra).
"Many fans believe the Cetra are actually an alien race, which migrates from planet to planet, due to a line Sephiroth says during Cloud's flashback in the English version of the game: "This Planet originally belonged to the Cetra. Cetra was a itinerant race. They would migrate in, settle the Planet, then move on..." This line may be subject to translation issues and a failure to clarify the interchangeability between "land" and "planet".
Elsewhere, the game's script states through Aerith that the Cetra were born on the Planet of Final Fantasy VII: "The Cetra were born from the Planet, speak with the Planet, and unlock the Planet". The act of "returning to the Promised Land", Aerith also speaks of, is an allusion to the return to the Lifestream, it being the Promised Land of the Cetra. This concept is confirmed by the Hoshi wo Meguru Otome novella in the Final Fantasy VII Ultimania Omega Guide. "
Jenova is a non sentient alien and parasitic organism not unlike Lavos that arrived through a meteor that gave origins to the Northern Crater.