Gantt Chart - Enhancing a Project Plan

See the attached .xls

I currently have developed a project plan with tasks listed and a gantt chart providing dates according to 'Start Date' entered and 'Days'.

I want to enhance this project plan to do the following:

1) Is there a way to lock down what a user can enter? They need to be able to enter the 'Start Date' (Column E7) and the Days Columns (starting with D7 -> D18). I don't want a user to be able to make any other updates to any other cells.

2) Can the Row be highlighted (say Columns B and C) be highlighted with where the status of the order should be, based on TODAY. For example, if today is 08/02/2016, Column B9/C9 should be highlighted.

3) My Gantt chart - starts with the 'Start Date', but only goes out as far as I manually do; Could this be automated to go out, for example, 60 days, on it's own?

Thanks!