You can't park directly at the Magic Kingdom. You would have to park at the Ticket and Transportation Center. This is DIRECTLY next to the Polynesian. As has been said at length - parking at the Polynesian is for guests of that resort. Besides, if you take the monorail from the Polynesian, it will probably take you twice as long to get to the Magic Kingdom. First of all, because you'd have to walk to the great ceremonial house, and then the monorail stops for a good few moments at the Polynesian as well as the Grand Floridian. If you just take the tram, the monorail will go directly from the Ticket and Transportation Center to the Magic Kingdom. Not to mention, when you leave, you will have to wait substantially longer for a monorail to get back to the Polynesian.
Absolutely. In fact, as I said just above - you HAVE to use the monorail.
As a ticket holder, you're entitled to use ALL Disney transportation including the monorails, boats, trams, and busses.
Have a fantastic trip!
And for the rest of you - there's far too much name calling and a rude tone pervading this thread. Cool it, please.