There are no sidelines, endlines are at runners discretion. Last night I saw two runners brilliantly use the water wagon to conceal their intended route and ward off defenders.
Full game was played with nary a single off side penalty.
3, 4, 10, 23, 74 reverses in course can easily occur, and usually do, on every play.
When a runner goes down, and the officials blow the play dead, the flag must still be ripped off... gang-ripped off if possible.
Serious injuries are frequent BUT.... a pat on the back, perhaps a bandaid, and they're back in the game.
This next I didn't know until last night... 10yds, 30yds past the line of scrimmage you can still throw a pass.
No need to wait until the whistle for a snack break... if the need hits you hit the ice chest.
Blocking is done using "The Force", no physical contact is made.
Crying IS allowed in Flag Football... also nose picking, flower plucking, daydreaming, grab-a$$ing, and occasionally switching teams in the middle of a play.