there's actually a very easy way to add different effects to different parts of the model. If you look in MagicaVoxel's 'render' settings, there are different options, with 'emission' being a glowing effect. you can select that option and then export that piece like that.
the 3d camera rotation is actually a quite simple process in blender! Here's a tutorial that should be very comprehensive!
size shouldn't matter. As long as you can move and zoom your camera, you can get it just how you want it~!