I have been using Omega fuel, which has an 18% mixture of Castor and synthetic lubricants, for three years and haven't had a problem with my engines. As for the plane: Just dial in some exponential with moderate rates. This will dull the sensitivity, yet still allow you adequate travel should you need it. Since this is your third plane, I assume that your orientation is good, you're familiar with all the flight surfaces, can fly the pattern inverted, can land reasonably close in a deadstick, and are able react quickly to changes in flight patterns. If you can do this, then you shouldn't have a problem. If any of these are issues, then a quick handling 3D plane like this could result in the improvement of your repair skills; if you catch my drift. Just make sure that you can react without thinking when flying it, is all.

NorfolkSouthern