Others may be able to address your specific questions. I just want to offer a general tip. You can often use the macro function of excel to find out what you need o do. Pull up a spreadsheet, click Tools => Macro ==> record new macro (call it whatever you want). Then preform the actions you want your program to do. The Click stop recording. The click Tools ==> Macro ==> Visual Basic Editor. In the modules folder of the macro you created will be the VBA code of the actions you Performed. This can often just be turned into VB code. Here an example using your post:
VB Code:
Sub Macro2()
Rows("5:5").Select
Selection.Insert Shift:=xlDown
Range("A2:A5").Select
Range("A5").Activate
ActiveCell.FormulaR1C1 = "=SUM(R[-3]C:R[-1]C)"
Columns("D:G").Select
Selection.EntireColumn.Hidden = True
End Sub
Here is a link to the FAQ here that may also be of interest to you:
http://www.vbforums.com/showthread.php?t=391665