Suggestion:

Add a feature to Excel which allows a sheet to be defined as a function in
another sheet, with names input cells, and named output cells. For instance,
if I had a complex sheet named "estimator" which determined an inflated
future cost of a room using inputs "seats" and "technology_level" and
produced the result "future cost", let me call it from another sheet by
setting a cell = "estimator(seats=50, technology_level=3, return
future_cost)" or something of the sort. This would be a wonderful feature
since it would allow more or less ad-hoc creation of powerful functions,
without needing vba.

Another feature which would be nice would be the ability to define cells or
merged cells as embedded controls (as in the control toolbox). The embedded
control would be in the cell, and would have its position and dimensions
determined by the cell. The control toolbox controls are great, but NEVER
print in the right places, and don't keep their positional relationship with
the rest of a sheet well.

That's it...