You can also use Windows Task Scheduler to open a FileMaker file at a scheduled time. Use FileOptions in this file to specify a script to be run when the file opens. This script can use Perform Script to start up a script in your external file and then use Exit Application or close file to close itself after it has been run.
This at least avoids the need for VBScript and exposing passwords.
I will choose your method, which I have done in the past also. I just had a wish to do all the scheduling within FMS, but your solution is better, considering the serious limitations within FMS scripting.