Heya. I'm Australian, so being on late by American standards is something that will happen for me on occasion. 
As for your questions, they seem to be based on faulty premises. You can already choose your nation, it's a component of your class choice. You start in the city with the guild for that class. (This kind of sucks for Limsa Lominsa.) This goes for Legacy characters too.
That said, my answers are 1) the ones that are not Gridania, and 2) every class, probably eventually ending up with every combat class at max level on all of my characters. Each would have their particular IC classes, though. I'll most likely specialise my characters to each concentrate on select crafting, and maybe gathering, classes since I'm not quite as fond of that gameplay and to save inventory space.
As for your questions, they seem to be based on faulty premises. You can already choose your nation, it's a component of your class choice. You start in the city with the guild for that class. (This kind of sucks for Limsa Lominsa.) This goes for Legacy characters too.
That said, my answers are 1) the ones that are not Gridania, and 2) every class, probably eventually ending up with every combat class at max level on all of my characters. Each would have their particular IC classes, though. I'll most likely specialise my characters to each concentrate on select crafting, and maybe gathering, classes since I'm not quite as fond of that gameplay and to save inventory space.
