i suspect a) testing if it really runs well,
It still runs almost as fast as XP, OpenGL still runs exactly the same speed.
I am not talking about Max3D specifically, because I don't need to.
it depends on what you'are exactly doing
No it doesn't.
i don't know how much benefit you will get out of a 64bit version yet.
Same as you do on a XP64 bit system - none (or, slightly less due to 64bit data translations taking up more space in the 32bit environment).
Are there any x86 commands on the 64bit side beside of addressing larger memory which would make sense already?
No, because to do that you need the entire exectuable to be 64bit and Max does not have that capability.
Will need rework on the openGL as well if it isn't in there yet.
Max3D won't support anything that isn't in OpenGL.