I'm a self taught lone flyer mostly so rudder habits are organic I guess. Took a couple of months before I even realised what "bank and yank" actually was, lol.
I started on RET as well and I was so nervous to do the 3 channel AET for the longest time. Now that I have flown a lot over the past 9 months I would have to say that if I was to teach a newbie I would go straight to the AET. If you do your next plane and because you already have the rudder experience I would say don't short yourself and cut in some ailerons, it doesn't get any better then that.
If you like the biplanes but don't want to jump into the 3D stuff go with the Baby Blender. I did mine as a 4 channel and it was great, makes for a great trainer as well. Easy to fly slow, easy to fly fast, still maneuverable as it gets and it looks so cool in the air. This pic is just after the build...
And here is a teaser vid... the end was a landing, I have gotten better at it now, just a testament to how strong you can build this plane
I did do some mods to it like lengthen the tail by 3" to make it more stable in the pitch axis, put dihedral in the top wing for roll stability, then swept the wings back some and made just a single cockpit, just cuz it looks cool