Your tires would definitely have to rotate if you are speeding !
In my area it costs $20-$32 to rotate and balance the tires.
Rotate tires 2 front 225 and 2 back 245
Sure, you can balance the tires. Any place that sells tires can balance your tires. You cannot rotate the tires as you have already stated they are not the same size. Balance but do not rotate.
It's a good idea to rotate your tires every so often.
On average you should rotate your tires every 6000 mile or 6 months.
Proper way to rotate tires on C240
You cannot rotate tires on a vehicle when the rear tires are wider than the front. They must stay where they are,
Rotate your tires regularly every 5,000 miles for the best wear. Rotate at the very least every 10,000 miles.
You don't need to rotate MY tires but, you need to when your car goes left or right when the wheel is straight.
I recommend you rotate the tires every 5,000 miles and balance and rotate every 10,000 miles. Important: Air the tires to the PSI listed in your owner's manual or on the driver's door post.
You should really rotate your tires every oil change to guarantee full even wearing on the tires but at least every 5000 miles or so