ujm
1. – 4
It is not completly clear, There was a Russian ban on peyos in trhe 1850s many beleive this is when attempts were made to “hide” them by putting behind ear, under yarmulka etc.
5. Long enough that hair can be grasped ie a few mm
6. They are less influenced by kabalistic ideas, al pi kabalah peyos should be long, not ever cut (some allow burning)/. al pi halacha as long as not removed completely (defined above) the peyos are long enough