This may not specifically answer your long 3 part question but this thread is old and I found this while searching today. Here is one shorter way to: "Wait until a process has finished." If you know the name of the process such as "EXCEL.EXE"
strProcess = "EXCEL.EXE"
Set objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
Set colProcesses = objWMIService.ExecQuery ("Select * from Win32_Process Where Name = '"& strProcess &"'")
Do While colProcesses.Count > 0
Set colProcesses = objWMIService.ExecQuery ("Select * from Win32_Process Where Name = '"& strProcess &"'")
Wscript.Sleep(1000) 'Sleep 1 second
'msgbox colProcesses.count 'optional to show the loop works
Loop
Credit to: http://crimsonshift.com/scripting-check-if-process-or-program-is-running-and-start-it/