1.
Crafting/gathering is typically the way to go for making gil although what sells and prices vary server to server (obviously)
This is not to say that you cant make money just from hunting stuff as a LOT of mats for recipies require monster drops. I would say get a retainer and toss what you have and wont use onto the mb (market board). You'd be surprise at how much random stuff is bought

2.
Yup.

3.
Yup again


5.
I found monk is fairly easy once you learn your basic rotation.
MCH is easy to play but difficult to get efficient damage out of. You will often feel like you aren't contributing much damage in parties :/