“You All Everybody” is the song that Pippin (whatever his name is in Lost, I don’t know) sings with his band

I had completely forgot that, but yeah, I did a bit of checking and while it's a very understandable mistake, you actually mean Merry, not Pippin. Pippin is played by Billy Boyd, who did not star in Lost, but Merry is played by Dominic Monaghan, who very much did, a character called "Charlie Pace". I sort of remembered a hobbit's face in there as soon as I read your comment, but yeah, wrong hobbit. :D

Also. I think not pressing the numbers caused a (apparently reversible) meltdown that resulted in a huge magnetic field like the one that pulled down the plane. Or something like that.

Pulled the plane down... to the netherworld? See, it's just not internally consistent, imo. Or was there like a gate to hell in a specific airspace if you flew through it you'd crash on the island or what the hell. It just doesn't really work. Also I think I remember that Locke line, or at least context. Wasn't he like paralysed before they crashed, or something, and he didn't like people telling him what he's capable of because of that or smth.