but autotab, you can not control the time for individual screens, some need longer times.
Opening a set of files with their default program is easy, (you just tell the system to open the file), cycling between them is easy, (switch between visible windows), even having different times for each file isn't too hard - the problem I see is if you have multiple files of the same type.
eg. .xls - these will normally open as tabs within the Excel program, (IIRC). So not only do you have to switch to Excel, you then have to find the correct tab and switch to it - and there's no guarantee that the method of switching to a particular tab is consistent across programs.
You may be able to force each default program to open each file in a new window, however this requires being able to pass a parameter to the program to tell it to do it, (possibly), and there's no guarantee that the same parameter will work for every default program. To get around that, the easiest way would be to edit all the relevant filetypes so the default action is to open in a new window, (if the program allows multiple instances).