I don't use the EA app at all, so I am unable to help with running the game through the EA app in offline mode.
However, my game is installed completely from disk only to version 1.67. To install this way, your copy of The Sims 3 base game disk must be from before 2012. All of the others can be later, but if you install a later copy of the base game disk, it will force you to install Origin and then update to the EA app.
Check out The Sims Depot's How to Join the 1.67 Club, or Downgrade Sims 3 to 1.69: A Comprehensive Guide.
Things of note:
1. To purchase SimPoints, you may need the EA app. So if you want to buy them, install the EA app on a different computer. If anyone else knows a better way, please share with the class.🙃
2. Install the Superpatch for version 1.67, not the one for 1.69. I can't find my copy, and the link on the NRaas site doesn't appear to do anything. Does anyone have a current working download link for the 1.67 patch?
3. ALWAYS uncheck the box for installing the EA download manager or Origin every time you install a new disk, or you will be back to square one.
4. There is also a Create A World tool specifically for the version 1.67 installation. Does anyone have a current working download link for the 1.67 CAW tool?