If you select the "Wheel" tab in Control Panel - Mouse, it is set to 3 lines for each wheel "notch" by default. By reducing the value to 1, you can gain a finer control of 2 finger vertical scrolling with the touchpad.
You could do the same for horizontal scrolling, but I prefer the default 3 lines.
In the "Pointer Options" tab, I have increased the pointer speed to the maximum "Fast" value to cover more real estate quickly.
Pointer Options tab.jpg
I have the Sentelic touchpad running the 220.127.116.11 driver. I suspect this will work for other Sentelic (and perhaps Synaptic) drivers.