C&C 33-2 water strainer installation error and 2GM issue

Last week Windstar developed a noisy exhaust note, not unlike an unmuffled motor cycle engine.   After a minute or two, and some higher RPMs, it would settle down to its usual quiet gurgle.   Obviously this was an issue with an intermittent absence of cooling water, but why?   I checked underway and the water pump was turning, its hose seemed pressurized.  I also checked the water strainer (as best I could underway) and clearly water was being pulled through.   This left the mixing elbow and the heat exchanger to consider. 
I read over the very well-written shop manual, and went back at the boat where I disconnected the short hose between the heat exchanger and the mixing elbow, connected a length of 5/8" heater hose to the mixing elbow, and blew through it just to check for resistance.  The pleasant gurgle flashed me back to high school, and the ease of blowing showed that the passages were free of serious restrictions.   I put the hose on the elbow exiting the heat exchanger, and started the engine.  No water, checked the water pump and noticed it was now not turning.    Tightened the belt and problem solved. 
I had set it quite loose and it worked fine all season, only now getting glazed to the point that it slipped at low rpm or until it got warm.  I had dismissed the most likely source of trouble - the pump - because I service it every year, and because I had assumed any problem would involved a completely failed impeller.      Anyway, lesson learned...or probably not.   But, that's not the point...  I found some other stuff.

First Issue:
The 33-2 has its raw water strainer mounted in such a way that it cannot be easily checked or cleaned.   See the photo below where I managed to crop out the heater hoses above, but, in order to lift and remove the strainer basket, it was necessary to remove the coolant reservoir, by sliding it upward off its bracket, but in order to that, it was necessary to unscrew the two P clamps securing the hot water hoses.  (you see those in the photo below)

The solution (below) is simply to move the coolant reservoir bracket to starboard, and move the coolant hose p-brackets upward slightly.   There was enough play in the hoses that this was no problem.  

Second issue:  
When removing the hose connecting the heat exchanger to the mixing elbow, the small elbow/fitting on the heat exchanger came off in my hand, despite what appeared to be a securing set-screw holding it in place.   See below.

That screw (the Philips head, clearly visible) engages a groove in the elbow and this holds it and its sealing o ring in place, allowing a secure seal with 360 degrees of rotation.   On mine, the screw was pitted and flush with the bore, and did not penetrate into its receiving groove in the fitting.   Over time it had eroded or corroded, had become effectively shorter and no longer secured the elbow.   In the photo above, if you grabbed that elbow and pulled hard, straight up, the elbow  would lift out of its bore.   When running, coolant pressure is not adequate (I think) to overcome the tension placed on the joint by the hose, however the screw obviously needs replacement.  Yours probably does too.