I agree with most of your thoughts about the shinies - except Reshiram/Zekrom. After looking at them, Zekrom actually looks more robotic, while as said, Reshiram looks more angelic. I think for Zekrom, it is representing the underground, or something like that, because whenever I look at the shiny form, it looks like metal and robotic, idk. I just think that well, for Zekrom... it's the best they could have done. XD;
Oh and Meguroko's evolutions colours are terrible compared to their normal forms, which look much more like Crocodiles than... whatever they look like now. They looose the effect of being scary.
Also, congrats on Meraruba,Tachibana Azumi :)
(Wow everyone seems to be getting shinies easily)