You'll find the C-Max a wonderful towing vehicle. I tow a 1450 kg fleetwood Volante with it, and my main problem is keeping the speed down- you don't know the van is on the back. If you know the Cat&Fiddle, I was towing up the steep bit at 55, and catching up to cars!
The downside is that the front wheels are a bit light with such a big van on, so it's a bit frisky on country lanes in the wet.The other problem is wet grass, for the same reason. However, I have'nt had any problems reversing it- it's sometimes the only way to get it off wet grass anyway.
Expect 30mpg+, but you'll only get that in 5th @ 56 mph. Cruise control would be good!