Newtractor,
Congrats on your new machine. Those 3525's are really nice.
As others have stated:
*Lift the harrow before you turn. All of your runs should be in straight lines.
*Don't worry that your front weights are causing a problem. Actually, they will keep the front down as you lift the harrow to turn. They are not going to cause the rear of your tractor to loose traction. Just isn't possible.
* Do as you have said, and experiment with the gears in low range. Do not do any heavy work in high range. The heavier the work, the lower the range. However, you don't want to creep along the field like a turtle. If you are plowing about as fast as you could jog, then you are probably going fast enough. What you want to look at here is how the speed you are plowing affects the quality of the plowed ground. As you plow, the front disc's will throw the dirt out away from the center. Then the rear disc's grab it and toss it back in towards the center. Now, the plowed path should look smooth. If you see a center strip, like you are making a V, adjust your harrows by screwing the top hitch out. This will lower the read and and allow it to grab more dirt. If you are getting a hump in the middle of your plowed run, screw it in, because the back is biting too much. When you got your harrows, the were probably set so that the disc's are straight across both fron and back. This isn't going to accomplish much set in this manner. Both the front and back disc's should be adjustable. Adjust them so that if you were siting on the tractor looking at them in back of you, the front disc's are creating a slight V towards you and the rear away from you. (Front v, Rear ^ ) You wil want to play around with this setting until you get that smooth pass once they churned up the soil. Might be better to work on this in soft soil that will give you a more consistent pattern.
* You need to make sure your tires are filled with fuid. Up to the top of the rim, not over from what I understand. You can discuss this with your dealer or do it yourself. I've had some dealers put "some" water in the tires, but not near enough. If flooded properly, that tractor will be hard to stop.
* You will have to work your lift as you are working a free floating harrow. When you hit a very soft spot, the harrow will run very deep and this will bog any 35 hp tractor. I like to control the lift myself. You get a feel for it after awhile. Come up a little as you hit those soft sandy spots.
* You can't plow as deeply running up hill as you can down. And by this I mean even the slightest incline. Might not look like much of a hill, but your tractor knows the difference.
Take your time and be careful. Have fun.