Fuel, if you tow you'll likely use about double the fuel you would if you drove just the SVT.
Tolls, you'll be paying the same toll for the truck as you would with the SVT plus most toll stations figure tolls for vehicles in tow by the number of axles on the tow vehicle and with your 2 axle trailer I'd say you'll pay double for tolls.
Comfort, well its tough to say, you know your vehicles so you know how comfotable each is. In terms of driving stress towing the trailer might give you a little more stress mostly if you get into trafic or tight spaces.
Plus, if you should happen to encounter less than ideal road conditions like construction or rough roads the truck and trailer have suspensions and the high aspect ratio tires to handle those conditions more-so than the SVT.
But, its all the less miles on the SVT, a good chance the car will stay cleaner and like you said if someone breaks down and needs a tow you can be the man of the hour and offer up trailer services and you could even capatolize on it and get some money for your services.
Isn't this one of the reasons you initially invested in the truck and trailer. Being able to trailer your cars to events.
If you happen to get restless you could always stop off at a rest area, unload the car, stick Kim behind the wheel of the truck while you let off some steam driving the SVT.
I'd say trailer the SVT and see what adventures unfold during the journey.
