Assuming the tires are 10" wide, and the 30" tall spec is accurate (15" from the center of the installed tire to the ground), and the offset of the replacement wheel is indeed a -2 and not a +2, the scrub radius is approx. +3.6". This will make for a lighter feel at the steering wheel at low speeds, and make the steering wheel much easier to turn while parking. It also allows for more clearance from the inside of the tire to the frame and a-arm at full lock. Since the factory scrub radius is closer to 0", perhaps a bit negative even, your proposed change will be for the better (unless you'd rather have a heavier feel at the steering wheel).
What this +3.6" means is that when you turn the steering wheel, the front tire rotates at a point 3.6" away from the center of the tire contact patch, and therefore "rolls" as you turn the steering wheel. To hopefully clarify this point, picture yourself sitting in a chair and holding onto a stick of some length. At the other end of that stick is your tire, attatched to the stick via a wheel bearing. While holding the "tire stick" with your arm extended, move your arm from left to right and the tire will follow a path, circling around you at a given "scrub" radius, that which is determined by the length of said stick. Now, remove the stick, stand up, and grab the tire and rotate it (not roll it) like you're spinning a coin on the table. If you rotated it long enough, you would "scrub" off the rubber tread due to friction, because although the tire is turning, it is not rotating like it did when you used the stick to turn it. That is what a scrub radius is.
There are a couple of ways to manipulate the scrub radius on a vehicle designed with unequal length a arms like the Maverick is. One, is to change the rim offset as you are proposing. This moves the contact patch of the tire either in or out (based on a + or - wheel offset). Two, is you can modify the ball joint location(s) on the spindle, in turn, changing what's known as the steering axis inclination. This is what I did on our race spindles (see attatched image). Three, you increase the tire diameter. Lastly, and you wont believe the simplest way, is to just lower your air pressure in the front tire. Here's why:
As the tires' rolling radius changes, so does the scrub radius. This is due to the fact that the steering axis is not parallel to the vertical plane of the tire, so as the centerline of the wheel gets closer to the ground, the dimension between the center of the tire contact patch, and where the imaginary line from the top ball joint, through the bottom ball joint contacts the ground (your actual steering axis, and imaginary point in space that is the reference point that the scrub radius is based upon), the dimension between these two point decrease if you start with a negative scrub radius, and increase when starting with a positive scruib radius. This is due to the fact that these two lines that I just explained, have a finite vector (that's just a fancy way of saying that they're not parallel to one another!). :sorry:Sorry, but you asked!