You only have "implement flow" (minus flow losses) so are not within their "requirement" - but that may not be a problem. It depends on why they have that requirement. Here's some info to arm yourself with....
There isn't much technical reason for a low flow spec on a drill. The post hole drill is a hydraulic motor. More flow will allow it to flow faster, but any flow at all will turn it at full torque minus momentum. And that is what you want. BTW, having an upper limit to a flow requirement doesn't make much technical sense either.
So that means those manufacturer's "limits" are quoted more to give you an idea of the size of the implement and the tractor it is built for than as a real technical flow requirement.
If you ask, I think you will find that 10 to 30 gpm is simply their range for the RPM that they feel the drill should turn at to be equivalent to a similar size PTO-powered post hole drill. At higher than 30 gpm, I don't know what happens. Extra flow could go to a bypass in the hydraulic motor, although most tractor remotes already have that bypass so the high limit is just as strange and reinforces my belief that the "flow requirement" is mainly for giving an idea of the size of the implement.
After you use a post hole drill for awhile, you will probably find that there is a lot more use for turning the auger slowly than fast. The big advantages to a hydraulic auger is being able to use full torque when it turns slow and also being able to reverse it when it gets stuck.
For your other question, no the steering flow is generally not available for implements. Steering flow tends to be set by a proportioning valve as a either a proportion of the total flow or as an absolute that has to be satisfied before there is any additional flow for an implement. Sometimes it is a separate pump entirely.
In either case, it is not available for implements when you are stationary. This is so steering is always instantly available.
The total flow is a sum of all the flows and is a useful engineering spec for comparing with the available horsepower. Flowing fluid costs HP, and the gpm is directly related to HP. A tractor that has a huge flow pump reduces the HP left to do other things - like move the tractor.
luck,
rScotty
