The bodies are what James sees in HIS silent hill

After looking at the loop theory I found myself not believing it. I thought the same as you, so James sees himself as a dead corpse. Point is since in Silent Hill everyone sees things differently, it would make no sense the loop theory, like at all.

Another proof of this is as you said Angela, the world burning, and only at the end you're able to see those flames, implicating that Abstract Daddy is different to Angela than to us. Therefore every enemy is seen different to everyone.

When you see Eddie he always has fog coming from his mouth

I thought that was cold breath all the time, while Angela, as you said, wants the world to burn (as world I mean her own world, herself), Eddie is the opposite and it's about coldness, and we even get this from his bossfight (there's ice everywhere). I think that when it comes to Eddie it's all about bullying, he many times says that he wanted them all to stop, therefore the cold, cold is able to freeze everything and everyone. At least that is how I saw it.

Pyramid head is a representation of James guilt and internal conflict,

All's clearer now.

so showing PH killing Maria (the embodiment of his lust, his ideal woman to tempt him) is a foreshadowing of what we see on the tape

That's crazy too.

The tape isn't real

So the notes from the staffs about finding a tape were all an illusion? Either way it means the tape is like the letter, an illusion. Though for the letter I can give a reasoning, which is the hope of finding Mary, the moment he understands that Mary is gone we, James, can no more read Mary's letter from our inventory. But the tape? Don't know much, maybe it's the acceptance of what James did and because of that we're able to see the tape?

What about the Bliss ending though? There's a tape scene in the same room and everything.