In no particular order:

Just what does 'Hidden" do for a cell? Try as I might, locked, unlocked,
with formula, without formula, etc.I fail to see any difference whatsoever
in the behavior of a cell that is marked "Hidden" and one that is not. If
one could actually hide the contents of a cell without messing around with
the cell format it would be a Good Thing.

How does one reduce what Excel thinks is the size of a sheet? Assume that a
new sheet is created. Do the following:

With Sheets("mysheet")
.Cells.Delete Shift:=xlUp
.Columns(1).Formula = "=other_sheet!$A1"
.Cells.Delete Shift:=xlUp
End With

The first .Cell.Delete happens in a timely manner. The second and any
subsequent .Cells.Delete takes forever. It would seem that setting an entire
column irrevocably increases Excel's opinion of the size of the sheet to the
maximum. Or is something else happening here? If the size is being increased
as I suspect, how to get it back to some reasonable effective size?

--
Terry

"I said I never had much use for one,
I never said I didn't know how to use one."
M. Quigley