No, but your idea is slightly flawed.  Databases can easily be opened
without the opening script being invoked, completely bypassing your security
feature.  You need a combination of what you are doing with along with
built-in FileMaker passwords.

You set up each database in your solution with a series of identical
password and group combinations.  One password per group.  The group names
should be descriptive of what type of access the password allows.  The
passwords should be garbage that no one could ever guess.  Be sure to write
them down and put them somewhere safe, because you probably won't be able to
remember them.  There should be one password/group combination for each
level of access required in your system, from "none" to "system
administrator".

Set the "none" password as the default upon opening.  This will insure that
anyone opening your database outside of your control will not be able to do
anything.  Uncheck every option except "Browse Records" and set Available
Commands to "None".  Use the "Access Privileges Overview" to remove access
to fields and layouts.

Now, create an opener database for each of your password/group combinations.
It's only job should be to open with the appropriate "garbage" password as
default (to match it's access level defined above) and have a script that
you will call externally which should then open your main database,
effectively passing the appropriate "garbage" password and allowing the
level of access desired.  The final step of this script should close the
opener database.  The default "garbage" password should allow "none" access
in the opener database, regardless of the access it grants in the main
database.  Remember to add a password with complete access for when changes
are necessary.  Also, include a default opening script which does nothing
but close the opener database, meaning it won't function if you open it
directly.

On top of this, you put your custom password/group setup.  When an
appropriate user name and password are entered, the script is called in the
opener database that matches the access level for that user.  The FileMaker
passwords never get changed.  Do whatever you want with the ones in your
custom setup.

I can send you a set of example databases I created a while ago, if you
think that would be helpful.  Email me at schwandtg at aol dot com and I
will see if I can find them.  If not, I'll recreate them, but it may take a
little longer.