I am trying to do a similar thing. So far I've found that when you customize a screen, If you edit the grid (click "edit" at the top right corner of the grid's row (not the "edit" for the section) when you're looking at it on the "Customize" screen) in Step 5 you can set it to allow editing of the entries with an "edit" link, and in Step 6 you can tell it to add a new entries into blank lines inside a grid with a "New" link