Recently returning CMDR looking for some quick advice:)

Is there a faction I should align myself with? Does that mean I do only their missions?

Is it possible to be a hauler and bounty hunter on the side while also doing CG's? Is that profitable? I want combat badly but I also want to haul and possibly mine.

Do some ships cost less in other systems?

What's th3 best ship I could get if I wanted combat/haul?

Thanks.