For me that's exactly the desired effect becuase I banned you because I don't want to play with you. That's the point, it effects me, not the others. In other words
---- it protects me, not punishes you ----
About multis/metas, no it doesn't solve the problems, it helps solving the problem. They still have to be banned by mods, but they don't ruin others' games.
About the ludicrous situation: if you are banned at 15 people it's pretty sure mods know about it and you are already banned from the site. Still, if there's no auto-kick then you wouldn't notice you are a bannee at 15 people. If there's the 1 phase delay, it solves. Also at live games, you have to wait until it starts anyway, so there's no need to have auto-kick at live games, just at regular ones. Still, you could join regular ones to see, you kick someone or not, so I'd still prefer the 1 phase delay.
Or even better, when the bannee joins the banner gets 1 phase time to leave from the moment the bannee joined. This results the game will only have a delay if the bannee a) joined as last b) the game would fill up earlier then 1 phase later as the bannee joined. This reduces the probability of having a delay in the game start, and every player have to be around in 1 phase time anyway, during pre-game phase as well, since it could start any minute.
At live games, you could leave until gamestart