Robert,
You are welcome, let's see if we can get you on track....
First of all, hovering a single rotor, collective pitch heli is not easy...in fact, it's one of the hardest "steps" you'll encounter. Even now, after I've been flying for over a year, it's very difficult to hold a heli in a motionless hover, it's practically impossible in fact...it's not like the coaxials at all!!!
Hovering a single rotor heli requires constant small inputs in the cyclicl, rudder and throttle controls to keep in in a "perfect" hover, so it's going to be alot more of a challenge than the coaxials ever were...when you get some free time, go back to the coaxial heli on Phoenix and see how effortless it hovers compared to the B400!
The basics of setting trims in a hover is to acheive the most neutral hover possible, or as still as possible with no cyclic (right) stick inputs....you'll never get it to hover "hands off" for more than a few seconds, for reasons stated above, only coaxials can do that, it's the nature of the beast...
I've often heard it said that hovering a single rotor RC helicopter is very much like trying to keep a marble centered on a sheet of glass, by tilting the glass in whatever direction it takes to keep the marble centered...a pretty good analogy, I think...
The trims are there to give you a center point on which to work with the cyclic stick...so the better the cyclic is trimmed, the easier your job will be to keep it in a steady hover....so taking some time to trim on each flight ( a few seconds of hovering) is a good idea/practice. The point is not to get the heli motionless, but to keep it as close to centered with the right stick in the center as possible.
The narrow range of adjustment is normal, it takes very little input on the sticks, or the trim to make a change in the cyclic control of the swash/rotor head...
It will get easier with time and practice, I promise! At this point, I can't actually hover completely motionless, but pretty close...and I do it almost second nature...there is no substitute for stick time, both on the sim and especially in real life!!
Keep up the practice, and it will pay off!
Here's a short video of me practicing with the Trex 500 hovering....granted, it's a bit more stable than the B400, no doubt...but it's all about practice...I got a little bored, so I blipped the throttle a bit...lol...enjoy!
http://www.youtube.com/watch?v=iF3auuc8NuA
Have fun!
Glenn