First I was wondering what in the world you were posting... then I just clicked "Edit" to see what you wrote... and I saw that Groudon. Pretty cool I suppose.
No not at all... personality does not affect Hidden Power's type. Personality if you refer to "Alert to sounds" and alll come from IVs... which also affects Hidden power type.
It was based on DV/IV... or differentiation/individual values. It is the same as it is now.
Gen IV.. Eevee and Porygon Z had it since Gen IV.
Nah, the same exact thing happened for me. I hate carrying stuff specialized for HMs. I think all you need is Strength really...
Look at Mightyena, the BITE Pokemon. Feraligatr, the Big Jaw Pokemon... none of them are described as the species they actually are.
Sure why not?
Team Plasma? Oh boy. And wow Reshiram is using Fire... nice.