Kids are playing soccer with all kinds of weird goal sizes, the standard one at the schools I've seen was about 50% the size of the "real" ones. Nobody really talks about it because it doesn't matter as long as it's the same size for both sides.

Kids are also often playing with 1 goal and 1 goalkeeper and 2 teams trying to score (you have to move past half the pitch after regaining possession before shooting)- that way on 1 field you can have 2 games going on at once and only 1 person has to be the goalie in each of these games.

And we've played soccer on random backyards - you just put 2 backpacks as the goalposts and you're ready to go. I think the focus on rules and dimensions is very american, kids just want to dribble and shoot, the score and the minute details aren't important :).

As for replay they were introduced in high-level football last few years. It's called VAR and most fans hate it because it spoils the celebrations after a goal is scored and you have to wait to know if it's really a goal or not.