jhf - you don’t need to apply PTFE on the push fitting connectors where the PTFE tube slots in. Be careful undoing those. It’s truly push fit, similar to a John Guest fitting.
So definitely not on 1 and 3.
If you need to unscrew 2,4,5, 6 so you can ultimately unscrew 7, then yes, you’ll need to apply a few turns of PTFE there too.
I’m no expert: DavecUK can confirm. 👍
Edit: Dave replied while I was typing. I think he meant 1 and 3. 😊