I have a spreadsheet that has been built for our Customer Service unit to
record enquiries - they asked for the spreadsheet to change the row column
depending on how old the enquiry had got before it was completed. For this I
have used the following conditional formatting:

Condition 1
=AND($A4<=TODAY(),$A4TODAY()-5)
Condition 2
=AND($A4<=TODAY(),$A4TODAY()-7)
Condition 3
=AND($A4<=TODAY(),$A4<" ")

What they also want is that the row turns grey once they input a completion
date - this is done with the following code:

Private Sub Worksheet_Change(ByVal Target As Range)
If Intersect(Range("H:H"), Target) Is Nothing Then
Exit Sub
End If
If IsEmpty(Target.Value) Then
Exit Sub
End If
Target.EntireRow.ClearFormats
Target.EntireRow.Interior.ColorIndex = 15
End Sub

However, and this is where I need some help, the code that turns the
completed rows grey also knocks out the cell formatting i.e. cell alignment
and the fact that some cells are formatted specifically as dates - is there
any way to restrict the change to just the conditional formatting?

Also, any idea why (or how to stop the fact that) the empty rows sit on the
spread sheet coloured red?

If you can help me with htis - you're a star!