Need more info. What do you have for a radio? Does it have pitch & throttle curves? Is your gyro a standerd piezo gyro or is it a heading hold gyro? I'm knot familiar with the Futaba AG154 Gyro. How much gain do you have set on your gyro? If it is a heading hold gyro you don't use Revo Mixing. Do you have a pitch gauge,if you don't you have to get one(you need it). If you are hovering at full stick, I would say your pitch and throttle is not set up right.That is why your RPM is to high in a hover.That is why you are haveing so much problem with the tail. You have to have your throttle & pitch set up right and then you can work on getting the tail set up right. You really should try and find someone to help you set that thing up, it will save you alot of time and money. If you have to drive 2,3 or even 4 hours it will be well worth the drive. Have a look at this site and see if you can find someone that is close to where you live. Then send him/her an email and see if they are willing to help you out. I'm sure they would be happy to.

http://www.p-locate.rc-helipad.com/