An adaptive website, wordpress, mobile friendly - repost

Admin section page template for easy data entry to be displayed on public facing pages. I would like to build a very simple website that will predominantly be used by mobile users, so it needs to be very mobile friendly. Basically looking like an app in theory. The idea is to use this in my company. The manager of one of our places would go on this very user friendly back office software and be able to put things on the website. I would like the manager to be able to upload rotas on it, so that the different staff in the group can sign up with their e mail address and access their different rotas to see what shifts they are working. I would also like them to be able to have access to a mini calendar (in list format or calendar view) so they can see the different events that are coming up. This would also be inputted on the back office software. I would also like a news feed that the manager can type in to be able to notify the staff of any changes. Ideally I would like this to show as a notification to the user. In the back office software I would like to be able to remove users in case they leave the company. I would also like the user to be able to message the manager and it go straight to their e mail address. There are plenty of bits to this with a bit more detail and I have a working idea of what I would like but would like to improve it.