Contact three or more granite companies in your area and have them come out and measure your current layout, give you an estimate and install date. Most of these companies will remove your old counter tops prior to installing the new ones. You can save a few bucks if you demo them yourself. Make...
Yes, I prefer to get all the mess out asap. You can always do one room at a time, but if you can do it all at the same time it will go faster. Don't worry about pissing the contractors off we are used to it!
Do all your demolition first, next do all your replacement work/ new work, then painting and finish with your flooring. You can stage your interior work separate from your exterior work. Good luck if you are living there while remodeling.