The navigation is a bit awkward on my PN820 and there is a tendency to fat finger the Internet Explorer button. I'm on the 'pay-a$-you-go' data package and would rather not pay for internet browsing done by mistake.

Is there a setting or regedit that will allow me to disable IE so it doesn't connect automatically to the internet?

Try this.
I found it on the Q forums, but it doesn't appear to be Q specific.
You will need a registry editor.
I am very curious to find out if the works on the PN-820.

Adding Password Protection Before Using Data Connection
If you want to be prompted for a password when you access the Internet, do the following:

1. Navigate to:

HKEY_LOCAL_MACHINE\COMM\ConnMgr\Providers(7C4B7A38-5FF7-4BC1-80F6-5DA7870BB1AA)Connections

2. Inside the broadband and express keys, change requirepw from 0 to 1.

3. Perform the same action in the following key:

HKEY_LOCAL_MACHINE\COMM\ConnMgr\Providers(EF0974C-4C98FF6-AEF805DC0E8E)VZW BROWSER

4. Perform the same action in the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\MOTOROLA\MMS\PROFILES\ VZW MMS

When you attempt to make a data connection, you should be prompted for a password.

You can also just set your homepage to about:blank on IE and that will avoid unwanted web surfing right at the start of the application.