[ARCHIVED] Sub-account admin role and course creation inquiry

[annzinen]

Dear community! 
It is my first post and I have many doubts due to the specific situation I have. I coordinate a global project with 300+ students from different universities (around 15) and 20 professors from all over the world. Everyone (professors and students) should be invited by me into the same course.
For this global project, my University who has Canvas for Institutions created a sub-account and gave me an admin role.

1) First of all, I am not sure if they did it right as I cannot create any courses within my sub-account, should the main admin of the institutional account create courses and then I tailor them and invite participants?

2) Secondly, I am not sure if the admin role is the best for me? I need to be able to invite everyone into the course, I also need to be able to create quizzes, assignments, and participate in the discussions as the rest of the professors. Will I be able to do this with the admin role of the sub-account? What would you suggest?

3) Due to the complexity of the course and the project, it is necessary to have a professors-only discussion forum. What is the best way to have it? So that only professors have access to it and students cannot see-read it? Initially, the only thing I was able to figure out was to have a not-published discussion. However, it is very risky, as I can have non-experienced with Canvas professors publishing it by mistake, which will result in 300 students reading it. What other options would you suggest?

4) Last question, related to the previous one. How can I restrict professors from other universities not to change settings in my project-course and not to mess-up with quizzes and other assignments? They would need to be able to see students and grade students submissions but not to be able to change assignments and other settings. Will giving them access as a TA will work? My university has an institutional account. What would be the best role for external professors in this case? 

Thank you so much in advance, I am already grateful this community exist and hope you can guide me!