Hello? I'm from GHANA and currently I'm in china and I have finished my studies,

I have registered a company here and I have the company registration certificate and I've also finished my foreigner medical examination here in CHINA. Now I've presented all my documents to obtain a work permit and then get my Invitation letter that I can use to apply for my visa when I get back to GHANA.

My current X type expires on 31st of July, So I will exit China and go to Ghana and wait for the work permit and the invitation letter to be sent to me when they are ready.
I have only 3 questions now.

1, How long does it take to get a work permit and invitation letter after submission of all needed documents at the Chinese bureau?
2, Will I just have to fill the forms at the Chinese embassy in Ghana and add my work permit and invitation letter to get my Z type to China? or there are other things I need to do?
3, Will the Chinese embassy in Ghana request for my medical examination certificate or the complete medical examination reports I had from China again? If yes should I give them the original or a photocopy?

Please let me know what I need and what to do before I get to Ghana? thank you!!