1) People level in alliances now. We do Grounds of Valor in Gusgen mines from 10-35ish. This takes about 5-6 hours and is the standard leveling path now. The alternative is solo or duo with friends. That said its a shorter run if you start from Bastok, but it sounds like you know the zones well enough it won't matter.
3) At 30 start the Abyssea quest. You won't go into Abyssea until 75+ but you need to start the quest as early as you can to start building up time to use inside Abyssea.
Any more questions?
Edited, Jan 10th 2013 6:10am by TikkaofLakshmi