Modifications to Client/Admin Portal

I have bought the below Client/Admin system from codecanyon and basically everything works perfect but I have some modifications that i would like to have implemented if possible: 1.: A Note function on the admin part which can be linked to a client (but only show to managers and admin) eg. this could be used to hold information about how to access client systems, contact persons etc... 2: A file section - which also should be assigned to a client and afterwards give to possibility to upload files in different admin/manager created folders - possibility to give client access to files ... eg. checkbox with assign access to client if possible these changes should be made so it is still possible / easy to upgrade to future versions of the system [login to view URL]