#2
Sounds to me like a mixture of natural and melodic minor.
WHY IS EVERYONE IN THE PIT A FUCKING METALCORE KID
#3
Just by ear it sounds Mixolydian, but I have no idea so don't take my word. It looks like he is playing a melodic minor though.
"Men profess to be lovers of music, but for the most part they give no evidence in their opinions and lives that they have heard it." ~Henry David Thoreau