Let me start with question 6. I disconnect the hose that comes off of the hull pickup where it enters the impeller pump. I then connect a clear tube to the pump and drop the other end into a 5 gallon bucket full of RV plumbing antifreeze. I remove the thermostat at this point too so that I don't have to have a hot engine and can be certain the AF goes where I want it to.

Start the engine, and in maybe 60 seconds all the fluid is now in the engine. This basically lets the impeller do all the work.

At this point, the AF will be starting to come out of the exhaust. That's where all cooling water exits the engine.

For #2, you might not have a strainer. What you found in #3 sounds like it might be the transmission heat exchanger. Does it have 2 thinner hoses coming off the side of it? If so, that circulates trans fluid across a heat exchanger that has the incoming water flowing through it.