Radiator positioning: From my point of view It would be the same as putting a car radiator in the back seat. it takes heat away but by no means far enough away. The koolance setup requires that the Rad. and pump be located ABOVE the chip heat-sink. Making the top of your box a rather ideal location. Have you a means to open a discussion with the manufacturer? The sensor you're concerned about losing, What does it feed into... i.e. does it turn on and off your pumps and cooling fans as needed? Or does it just report temps to a read out? I hear you on the age vs experimentation front i think age naturally gavottes to the tried and true.Not a bad approach to maintenance, but progress tends to slow.