I can speak to the "how's come different tobaccos taste" thing.
I can grow two identical plants next to each other and make them both taste different.
It's all about "you are what you eat".
There's a fuente movie out there that shows how the guys choose tobacco for their blends.
Burn a leaf, whiff it up, burn a few more, and you can see in your mind's eye what they'll be like together.
Roll a few up and see if it works.
If it sucks, tweaking ensues.
Same as cooking, really. It's gotta be tons of fun being trapped in a gorgeous tropical climate playing with tobacco leaves all day.
