I agree with Old harry about the bucket. I like a gently overflowing bucket in the cockpit (but you do have to be careful not to siphon the entire bucket full into the exhaust system when stopping the engine)

You say it is directly cooled but you refer to a heat exchanger. You mean it is indirectly cooled?

The 74° thermostat would probably be correct for a salt water cooled engine but one might expect to see one rated at a higher temperature for fresh water cooling.

Actually the Workshop manual says
Opening temperature 79.5 - 83.5C
Fully open 93.5 - 96C

Your running temperature does sound reasonable but with a better supply of cooling water it may tend to run cooler.

Re this "addiction" to Easy Start. They don't become addicted it is just that people don't fix whats wrong, they just keep on using the Easy Start. It can be bad news for diesels as you have no control over the time of the ignition, with petrol engines the Easy Start does not ignite until the spark ignites it at the correct time. It can also be dangerous with engines fitted with preheaters in the inlet manifold