Why Use Spiral Mixers How Do I Use A Spiral Mixer And A Dough Roller Properly?

How do I use a Spiral mixer and a Dough Roller Properly? - why use spiral mixers

My friend left his stuff here with me, if you can move to another country. I'm using, but have little experience.

I decided to make buns, steamed meat of identification with them, to ask for help on using these things

I just do not mix all the ingredients of the dough in the bowl? or I should become a ball in the first box-mix before they mix in the? I've tried to work the ingredients into the bowl directly mix, but not very good. Am I doing something wrong?

On the role of the dough, which is their main goal? Why do many people believe it to use? I wanted to leave the dough to spend about 35 times is the best

Sorry for the Newbie questions!
Thanks in advance!