#1
heres a few attempts at that bridge part we all know from Creep

http://www.box.net/shared/thdbloxpfgqdp18c4oqh

id like to think the first long "RUUUUUUUN" sounds semi-decent but the rest are pretty shit, I tried approaching the note differently each time so I guess I'd like to know what it is I'm doing right the first time and ****ing up in the others so i know what to avoid

also how am I doing tone-wise besides that? is that high A considered "mixed voice" or is that something else completely?
#2
First note is good, second is not.
You have a powerful voice! With practice those notes will come with ease, i can hear it in your voice. You have this natural blending between the registers.
To answer your question: First attempt is definitely the best, hard to hear where you strained the most, but that sounded most powerful.
And yes you are entering your mix-register at that point. It might not be something your think about when doing it, but yes you start to mix falsetto and chest voice. With time at practice you can hit some decent high notes, trust me.