Sodbuster;
Yes you can control the pump and no it wont burn it up. Trust me when I say you'll need a good heat-sink and small durable fan as the pump pulls some amps and makes for a hot switch.
Myoldyougrold;
I'm sorry but as of yet I haven't seen even one pump that stops running or pressurizing when at or to a certain pressure. Any system that I have worked with, be it return(with an external regulator) or none return(without a external regulator) still has a return. Some having an internal spring pressure valve for release or an internally mounted regulator in the tank. One way or the other the system has a pressure regulator built in. So far the best I've seen is the flex fuel setup(single line, which has the regulator inside the pump assembly) !
Basically I'm saying that if the engines running the pump is running constantly by design. Electric or mechanical
Hell even the oldies on mechanical pumps have a spring release to ease pressure to the carb. (such as the one in the 57 ford pictured)
Its done right or its not done !
Hail HHO.