md3-files

I’m knew at using md3 files and I wanted to ask some questions

-if you make a tranparant model in a 3d-modelling program and convert it into an md3-file, is it still transparant?
if so, why is alpha-blending used to make 3d-models transparant if you can do it in a your 3d-modelling program?
for performance reasons?

-do most 3d-engines have there own engine to animate md3-files or can you use your 3d-program to do this(using ik or someting)?

-is asm used a lot in games?