3) it is NOT NECESSARY to remove the stat to fill the engine with AF, the way you do it (doing it this way 15+ years) is:
drain from the block drains, poke holes, same with intake drain if you have it, then drain by removing bottom of hose as in #1 above. Then after it all drains, reconnect bottom of that hose. Replace all the drain plugs, put a bit of Permatex Aviation on the threads of metal plugs. Disconnect the top end of the big hose. Now fill via that hose till the engine is full, it will take quite a bit and when AF spurts out of the thermo housing you are done. Re-connect hose no need to remove the thermostat.
I'm going to ask the stupid question. I can understand filling AF from the hose leading to the circ pump, but if the thermostat is shut, how will AF flow out of the t-stat housing so that you know the engine block is full?