No running it for a couple of seconds with out coolant wont hurt anything. Just dont give it time to warm up. You can run any type of coolant you want, just make sure that it is all the same. Get you a gallon of preston, peak, or what ever brand you want. Some people run the long life stuff. I would probably do that if I wasnt running engine ice. Engine Ice is supose to be the best, it helps your machine run cooler in the dead heat of summer.
At the least I would do a compression check. You could always pull the pipes off and just look in through the exhaust ports. Dont requires nothing but your time, and gives you some reassurance.