Water leaking from the purge hole in the pump means that the pump is shot.

Common problem.

Whole moving over 20mph the fans are not required. Airflow through the radiator will lower the temp of the coolant sufficiently. Even if you lose a fair amount of coolant while moving the temp can still stay low. As soon as you stip the low coolant level plus assuming the pump is not nopertaiong properly this will cause your temp problem.

M103 water pump changeout can be DIY - bit of slog though.


Don't know about your thermostats in your climate but the thermos here in the Southern Hemisphere are set to 87degree.