Howdy Mike. The 3500 number is the highest output that generator is supposed to make. It should be limited to no more than20-30 minutes at this amount.

The 3000 Wattnumber is what it is rated to run continuously. This is the number that you would take 80% of to get the longest life out of your genny. So you would want no more than 2400 Watts of lights. You could run 8 - 300's.

Yes, the GE lights are that much better. I've heard that they stopped making them though.[:@]So maybe it'd be best if you didn't get used to them.

The 12 guage cords will be plenty.

The wheels are probably not installed when you get it. The ones I've had just use a cotter key to hold the axle in. They are very easy to remove.

Yes, it can sit on the floor. Two things to keep in mind are not to let the muffler get too close to anything. It will put out enough heat to weaken aluminum. And you will want to put something like a rubber mat under the genny to reduce vibration that will be transmitted though the hull of the boat.

BTW, welcome to the asylum.