This is almost exactly what is happening behind the scenes of the current load case editor. The user interface hides the "1s" and "blanks" to hopefully make things more obvious.

Are you aware that you can take the current column titles drag them to the top of the window to make categories? You can also use those "filter icons" to create subsets of the load cases (for viewing and modification).

There is also the "group edit" view, which permits the modification of groups of load cases that meet a selection criteria. CAESAR II Version 11 also allows the import and export of load case data from/to Excel. Review the template for this, I think it will address everything you suggest.