1.we all know riot have our hardwares id so let's just say somehow they connect out hardware ids to our main ids
2.or riot should connect our network I'd (ip address to main Account)
Unrated my friend. Yeah people can say that unrated isn't the same level as competitive, but to learn mechanics and stuff you can do it in there or even custom games. You can get better with those agents with time.
Learning to use agents in an elo below yours (playing competitive), in someway or another, it affects on the other player's experience. You are using a match to practise, make mistakes if needed (part of the learning process), same match where people wants to work in his way up on ranks and maybe get dragged. At the other extreme if you are good at peeking, strafing and aiming, you can outfrag everyone in a low elo game (which also sucks for the other players).