1:It won't start. The glow plug needs the power from the starter to heat up and ignite the fuel and air mix to get it going.
2:Not sure as I don't own a Tamiya nitro. If you can't get any answer here, I would ask Tamiya about it.
http://www.tamiyausa.com/contact/index.php
3:When you spin the engine with the roto-starter, you will hear the engine turning over, but since the glow isn't heated it won't fire.