Moving to CF10, Need help with Application.cfc

Question

I've been googling about how to work with Application.cfc since last week but I still have some questions and I can't find the answers.
My application is under the root (in unix) and there are many subfolders underneath it. Each sub-folder is hosting a different web application.
From what I read, I can create 1 root Application.cfc and then on subsequent sub-folder, when I need to have another Application.cfc on that level, I can create ProxyApplication (see below) and then create a sub-folder level Applicatin.cfc
So, when I set an application.DSN on my root Application.cfc, using proxyApplication I don't have to reset this dsn again in my sub folder level Application.cfc
Since my loginform.cfm and loginaction.cfm is right under root directory too,  I also set OnsessionStart in the root Application.cfc to handle user login. Then this means, I don't have to reset session variable again anywhere because session.username, etc has been set on the highest level.
Is this correct?
In addition, Am I correct when I do the following:
1. Since I have root level and sub-folder level Application.cfc, I should set this.name with a different name, am I right?
    On the root Application.cfc I set this.name = "StudentServices" because this represent the global application
    On the sub-folder level's Application.cfc, I set this.name to "StudentServices_stdLoad" becaus this sub-folder only handle student load application.
2. On the root Application.cfc, I set the DSN to the application scope. So on the sub-folder level Application.cfc I can check if a particular db is working or not
    because as awhole, in the global sense, this web application uses more than one Databases. Each sub-folder may use a database that is dfferent than the other sub folder.
Am I doing the right thing? Please advice
Below is example of what I have, Thank you!
I created a root Application.cfc under the root directory: 
<CFCOMPONENT displayname="Application" output="true" hint="My Root Application component">
   <!--- Set up the application --->    <cfset THIS.Name = "StudentServices" />    <cfset THIS.ApplicationTimeout = CreateTimeSpan(0,0,30,0) />    <cfset THIS.SessionManagement = true />    <cfset THIS.SetClientCookies = false />
       <cffunction name="OnApplicationStart" access="public" returntype="boolean" output="false">
   <cfset application.MainDSN = "DSN1">
   <cfset application.ReportDSN = "DSN2">
   <cfreturn true/>
</cffunction>
 <cffunction name="onApplicationEnd" output="false">
     <cfargument name="applicationScope" required="true">  </cffunction>
 <cffunction name="onSessionEnd">
</CFCOMPONENT>
Then, in this root directory I also created a ProxyApplication:
 <!--- it's empty and it Serves merely to create an alias for your root /Application.cfc --->
 <cfcomponent name="ApplicationProxy" extends="AdvancementServices.Application"> 
</cfcomponent>
Then in the Sub-Directory, I can create a sub-folder level Application.cfc extending the root Application.cfc:
 <CFCOMPONENT displayname="Application" extends="ApplicationProxy">
    <!--- Set up the sub-folder application --->
    <cfset THIS.Name = "StudentServices_stdLoad"/> 
    <cfset THIS.ApplicationTimeout = CreateTimeSpan(0,0,30,0) /> 
    <cfset THIS.SessionManagement = true/> 
    <cfset THIS.SetClientCookies = false/> 
    <cffunction name="OnApplicationStart" access="public" returntype="boolean" output="false">
       <!--- ****** Testing whether the ADVUPGRD is accessible by selecting some data.****** --->
       <cftry>
       <cfquery name="TestMain_DSN" datasource="#application.MainDSN#" maxrows="2">
         SELECT Count(*)          FROM MyTable
       </cfquery>
         <!--- If we get a database error, report an error to the user, log the error information, and do not start the application. --->
        <cfcatch type="database">
          <cflog file="#this.name#" type="error" text="Main DSN is not available. message: #cfcatch.message# Detail: #cfcatch.detail# Native Error: #cfcatch.NativeErrorCode#" >
         <cfthrow message="This application encountered an error when connecting to the Main Database. Please contact support." />
         <cfreturn false>
       </cfcatch>
     </cftry>
     <cflog file="#this.name#" type="Information" text="Application #this.name# Started">
     <cfreturn true/>
   </cffunction>
</CFCOMPONENT>
    <cfargument name = "SessionScope" required=true/>     <cfargument name = "AppScope" required=true/>
</cffunction>
<cffunction name="OnSessionStart" access="public" returntype="void" output="false"> 
  <CFSET session.UserGroup = ""/> 
  <CFSET session.UserName = ""/> 
  <CFSET session.currentPage = ""/> 
  <CFSET session.loggedin = "No"/> 
  <CFSET session.userrights = ""/>
  <cfreturn/>
</cffunction>

Answer 1

OK.  It sounds to me like you really shouldn't be using a single root Application.cfc at all, if all you want to do is share some settings between your "sub-applications".  I would look at storing the common settings in an external file that all of the applications can read in.  The simplest way is to put the settings in a .CFM file somwhere outside of the web root (so it is not directly web accessible) and load it with <cfinclude> tag into the OnApplicationStart() method of each sub-application's App.cfc.  That .CFM file can be as simple as:
<cfset application.myCustomSetting = "blahblah">
<cfset application.myOtherSetting = "foo">
Alternatively, you can look at using a config file like this Ray Camden blog post suggests, and use the GetProfileSection(), GetProfileString(), and SetProfileString() functions as needed within OnApplicationStart().  You could even put ALL of your settings in
A third option is to store your settings in an XML file or in JSON format in a text file.  You could then write code to read in the XML file, and use something like xml2struct.cfc to convert the XML into a struct, then append the struct to your application scope.  If you go the JSON route, then just read in the JSON file and use DeserializeJSON() to convert it into a struct, and append it to the application scope.
What I think is probably the best approach is to use a community-supported MVC framework like FW/1 or ColdBox (maybe you already are, I don't think you've said so though).  One of the many advantages to doing so is that they have built-in "environment" support that can be used to configure common settings, depending on your environment (dev/qa/production).  You would handle reading in your external settings through the "environment" mechanism.
One other thing to think about: your login mechanism.  I think you want to use one set of login tools that is shared by all of the "sub-applications".  You can do this also by putting the login/authentication-related code somewhere outside the webroot of your applications, and then either set up a mapping to that location in CF Admin, or set an application-specific mapping in your various App.cfc files.  That way all the "sub-applications" share a common set of code for the login process.  I don't know how your login process works (do all users go to the same login page then get redirected into their relevant "sub-application", or does each "sub-application" have a discrete login page that utilizes common back-end processes to authenticate and redirect), so you'll have to judge how that is best accomplished.
Hopefully this gives you some useful ideas.
-Carl V.