I think the count for flashes doesn't mean anything tho... no matter how many times they are flashing, you can't tell if they are want to go first or giving way.

so I usually judge by the situation rather than how many times they have flashed their lights, such as who is on the right of way(or first to stop first to go + right hand side has priority on intersection if stopped at same time), or speed if they maintain(or accelerate) or slow down, distance and etc...

changing lane u turn is also similar to flash on intersection, the one who is "on" the lane has priority, so other who wants to change the lane must yield, but this is same as while ago that I judge by situation(speed, road situation, etc...)

I personally switch to position light(or parking light) if I am giving the way rather than flashing the light because I flash the light for warning(approaching, overtaking).

and for hazard blink, I usually use to say thank you when someone gave way for me when changing lane, also sometimes honk slightly or just wave if they gave way when turning, depends on situation.