Slightly off topic, but I just have to comment on one thing
but nobody I know tries to retract flaps in "an immediate turn after take-off." In fact, the general rule in airline operations is NO turn until above 400' AGL!
An immediate turn after takeoff is generally defined as normally a turn at 400'. Abnormally is another question. I presume we are talking about normal ops here.
Although not airline operations, we normally do 25 degrees of bank as low as 50' in the Kingair B200, out of some airports that have scheduled commercial service. I suspect they (the airline) do the same, since they regularly avoid hitting the hard stuff!