By handheld temp gauage you mean an IR heat gun (the type you point at an object then press a button to get a reading)? Dont be affraid to stop for a minute or two to take off the shell and get good temp readings (I have a whacking great big hole in the rear of my shell for said purpose). Dont be too worried about the cell voltages being slighly uneven either, I get the same thing with my A123s and zippy lipos; the safest minimum voltage for lipos is about 2.6-2.8v per cell. You wont get any warning lights or sounds either as the MMM has no way of making sound- the chimes are generated by the the esc pulsing current through the motor at certain frequencies to generate a high pitch buzz, and it cant do that & spin the motor at the same time.
You worry too much...
