You'll have plenty of time to do everything and then some. Personally 1 day at each park is enough for me but to each their own. I can't do more than 3 days in a row.
If you have the money, stay at a Disney hotel...super convenient and a few little perks. If not, there are a lot of places within walking distance to stay at a reasonable rate.
And yes, spring for the Genie + thing.