@Azodrak The floor looks like that because you tried to make cylindrical with a spherical image. To make and use a spherical panorama in AM you would either have to make an entirely new OCX plugin from scratch (which would be very ambitious), or, use GM for panoramas instead.
If you don't own GM then making a plugin should be cheaper with a free C++ compiler (or whatever other programming language that might be free), but more complicated.
If that doesn't suit you, then I totally recommend getting GM, as it is very cheap ($40 US)
@reneuend Yes, a tutorial is a great idea, that I considered before you asked. I'll get on it right away.