Sounds like some ignition tuning is in order. Install vacuumadvance at intake manifold to achieve at least some 20-24 degrees of advance at idle. This will most likely solve the hot running temps at lower speeds. No engine runs 'happy' with just 10 adv. at idle.
Base timing Mechanical adv Vacuum advance
I'll politely disagree. I have always run 10-12 initial at idle with out issue