Yes you can go on to the other sessions - I think the latter stages of the Bambino guide where you work on the catch and the rhythm and timing of the stroke will be of most benefit to you.
I wondered if you had worked on your swimming a lot - it looks like it! (you can tell as a coach). I think when you started out you were probably a bambino type but what has happened is that you have lengthened out your stroke and become a bit of an overglider cross (don't buy this guide, you don't need it right now and the bambino guide will steer you in a better direction). You fixed many of the bambino problems (the timing and body roll - good work!) but two of the most important ones remain which are feel for the water at the front of the stroke and getting more rhythm into your stroke. Both of these will come when following the bambino guide - you have all the sessions there.
What I would say is don't be afraid to be positive with your stroke actions under the water. By being a little more positive you will develop a better sense of rhythm and more natural feel into the actions.
You can also do the Arnie sessions, there's no harm in that and they will give you some variety but if you send me an email to firstname.lastname@example.org
I'll arrange a refund of the Arnie guide for you - you only deserve to pay for one.