This guide has their name in the international order lol so its Lee Know not Know Lee. Yep that is felix's real voice those 2 clips the person showed are all live clips, and the first one is taken by a fan, so yes that is his voice. He has amazing vocal range although his voice sits at a naturally deep tone.
Is it not technically in Korean order as his real name is Lee Minho so his surname is said first. But yeah its his stage name so order doesn't change, it's Lee Know
From what I hear everywhere, these boys don't have any set positions beyond leader and maknae(I guess also producers) anymore because they can all do everything. They're just split into subunits based on their strongest abilities(3racha, danceracha, and vocalracha). I'd say half of them mainly focus on vocal or rap while the other half do it all