Newbie questions

[mdtulp]

I just bought a sony bd-300 player and nearly 30 discs in the last couple of weeks. I noticed that they all have varying aspect ratios. One question is 1:85 an actual widescreen presentation? I have a 65" Mitsubishi dlp 1080 tv and only the 1:85 ratios fill the screen while the others dont fill the screen(which I dont care about as i love wide screen) It just seems like the older movies like good fellas, purple rain are 1:85 but so is Apocolypto so I am wondering how it gets decided on what ratio a blu ray disc is presented in.

Also im thinking about getting HDMI reciever but my player only has one hdmi output. Currently i just have my sound connected via the coaxil. I dont want to have to sacrafice the hdmi picture for sound as some places have said that you have to connect the player to your tv by another method than the Hdmi if you want Hdmi sound anyway around this?

Titles Owned
Pirates of the Caribbean 2
Night at the Museum
Departed
Apocolypto
300
Twlight Zone
Purple Rain
Troy
Flatliners
Fantastic Four 2
Spiderman 1-3
Unforgiven
Terminator 2
Memento
We were Soldiers
Underworld
dracula
dinosaur
deja vu
black hawk down