Pikmin/Headscratchers

I have concerns about Louie's grandma/auntie. Did she mistreat Louie or something? It's said that she always made Louie play outside with bugs when he was little, making me assume she didn't actually spend time with him herself. There's also the fact that she always made Louie finish everything on his plate, even if he was too full, making him the Big Eater he is today. Eventually all you get is letters from Louie's grandma/auntie sending preserved bug foods. Not preserved bugs. Bug food. Did she even feed him real food she made him finish eating? Sure, it sounds funny, but still, it makes me wonder...
The creatures. Since it's pretty much confirmed Pikmin and Pikmin 2 take place on Earth, it makes me wonder about the creatures. What the hell happened?! There's snakes with bird heads, caterpillars that spit rocks, strange Bulborb creatures classified as Grub-Dogs, creatures that resemble loaves of bread, freaky spiders, a strange fish like creature with a gun, the goddamn Waterwraith, and above all, Pikmin! How did these creatures come to be...? I know evolution would seemingly be a logical answer, but it doesn't seem to be the thing for most of these creatures...
In the ending to Pikmin 2, what happened to the Purple and White Pikmin? Their only home up to this point was the ship, but it had taken off to Hocotate. And, seeing as the Distant Planet's atmosphere is deadly to Olimar, Hocotate's atmosphere might be deadly to the Pikmin unless they -- or at least the cave-grown types -- have some unstated resistance to it. What really raises the question is the "first" ending when you only pay off the debt and do not get all the treasures: the ship returns to Hocotate, goes back to the planet, but the Purples and Whites are still inside the ship. Does this mean that for both endings, Olimar brought two types of Pikmin to his homeworld twice?