Maybe you could keep things simple by setting your desired screen size and then protecting the workbook with True for the Windows argument. The Structure argument is bypassed on purpose for brevity, which you could insert if you don't want the sheets rearranged. Example:
ActiveWindow.WindowState = xlNormal
ActiveWorkbook.Protect Password:="YourPassword", Windows:=True
This will take those min, max, restore, and close buttons off the active workbook window's title bar (not the Excel application title bar).
'To unprotect the workbook:
ActiveWorkbook.Unprotect Password:="YourPassword"