Drupal with Open Social Module

We need to build a website similar to https://www.policykitchen.com/ with the following specifications:
1- The user can suggest a category by filling in a simple form.
2- A simple statistic put in the homepage.
3- In the challenges page, the categories are displayed first then the user choose one
category to view its posts.
4- The comments and replies will be approved firstly by the administrator.
5- Unregistered user can not reply, just surfing the website.
6- There are two administrations levels, the main administrator has privileges to create, edit, and delete any category or comment. Or registered user.
The lower admin level has the authority to approve or delete challenges.
7- In the main page, the main categories will be displayed as icons linked to their pages, beside every category section, some links can be added to some sources files, pdf or external links.
8- The website front end with one language: Arabic (RTL)
9- In the group pages:
- Tags area, the member who will add a new topic or post can add tags (keywords) for that topics which can be used to easily reach the topic.
- Add 'Mail App', twitter, and facebook to share posts.