I don't know the reaction it would have on the coolant but I would advise you to flush out your system immediately and put in fresh coolant.
Do not run the engine with windshield washer fluid in the cooling system. Most washer fluids contain methane alcohol and is not the same kind of chemical found in coolant. I strongly recommend thoroughly flushing the system and using new coolant. It may be wise to exchange the thermostat. The problem with a foreign chemical circulating the system is manifold and head gaskets could be damaged and if you are unable to replace these seals it can cost thousands of dollars.
Probably the thermostat is sticking.
too much water added the overflow is designed to let out water.onece the radiator reaches the required pressure,the excess water is exhausted thru the overflow
The engine will knock.
I drille a hole in the top of the case and poured in some gear oil. It worked for a year or so.
it disloves
Saltwater kills most plants.
after a while it would be irritating
it bubbles up
If it is a lot of bleach, it will kill the grass.
Either it will not run at all, or run very poorly. Either is likely to do severe damage to the engine.
No it won't hurt it. If you only poured a little in the radiator I wouldn't give it another thought. If you poured a quart or more in there you probably need to get your radiator flushed before the temperature starts hitting any extremes. Aluminum engine parts can be a little touchy if they aren't heated and cooled uniformly.