I'd pick one coolant and stick with it. When my son bought '02 Focus it had some sort of yellow colored coolant that I cannot swear was Ford, car had 10K miles on it. The coolant over next year turned combination of rust color mixed with PURPLE (??!!) with heavy rust silt on inside of plastic tank. I flushed it and added green and no more troubles, had to change the plastic tank at the time because the purple had permanently stained inside walls.
I have no issues at all with water pumps but coolant type might well be the difference in 4 years pump lasting vs. 8, or not perceivable except during the very long term. I tend to change pump with my serp belt, hoses, stat, and timing belt, i.e., one big part changing party. Whole idea to stop multiple breakdowns, it must work, the cars never go down unless I bring them down.
“If stat in right system's bled by the time motor is hot, I NEVER bleed them longterm.”
If the thermostat is in correctly with the bleed hole facing straight up it bleeds into the small hose that goes to plastic tank. That hose bleeds fast, there is another going to top of radiator. By the time the motor is warmed up, the system is pretty much bled. I check one last time or maybe ten driving minutes later and then forget about bleeding, it's done. Those who say you must make a big effort to bleed these are incorrect or have changed the stock system up or put thermostat in wrong with hole not facing up. The stock system is set up to bleed almost instantly, that's the reason for all the extra (9 total ?!!) hoses.
If I add an extra washer to brace up the stat cover it goes between cover and thermostat, glue it up to stat with silicone. Washer may need a notch cut in it to clear the bleed hole, I did. It needs to be same OD as the stat with an o-ring on it and a hole in center to clear stat opening. I can make one custom fit from a suitable $1 hardware store washer with about 2-3 minutes with a dremel. The stiffness of the (.045" thick in my case) washer makes up for the plastic cover which tends to warp in at the 3 corners where bolts pull it in. The small leaks come from the looser area in between the bolt holes, it relaxes there to ooze coolant. Pull a cover and look at it close or put a flat fine file to it, I do that anyway in an effort to make it flatter. Don't do that unless adding washer, you're removing material there, less crush on gasket.
BIG note, many people crack those covers and housings by overtorqueing them, thinking they are still in the days of metal parts. NO-NO. All you are doing is squishing a flimsy o-ring, once you feel the cover or housing hit solid STOP THERE. Maybe just a tad more to be sure. Tightening anything beyond that is guaranteed crack city. I have 3 zetecs and have not lost a plastic part yet after changing stats several times, housings off the head too.