The event sequence you described is:
- right hand finger drag, followed by
- right hand finger lift, followed by
- left hand finger touch and release (tap).
When you click using yr particular method (w/ fingers from 2 hands on the pad), make sure to tap with yr left hand finger after releasing the right hand finger contact. That should help the kernel recognize a quick tap as a left click and (I hope) differentiate between that and a trajectory sensed as continuous on the pad, going from right hand to left hand according to the sequence above.
Experiment various avenues at length or possibly change the way you work with yr touch-pad.
1) Coasting:
First read the doc and make sure that "conventional coasting" is disabled. If you want coasting, make sure it is enabled as "edge coasting" only. Otherwise the type of sequence described above will lead to what I call "pointer movement leak" ("conventional coasting"), a behavior that consist in the fact that the pointer continues its rectilinear movement even after you have stopped driving it on the pad. Conventional coasting stops with a tap.
"Edge-coasting" on the other hand is only activated when you apply finger pressure on a pad-edge. It stops immediately as finger pressure goes below a given value.
2) Second, tweak Synaptics Tap Durations (273): 180, 100, 100:
The 3 values are:
Option "MaxTapTime" "integer"
Single touch timeout or maximum time (in milliseconds) for detecting a tap.
Option "MaxDoubleTapTime" "integer"
Maximum time (in milliseconds) for detecting a double tap.
Option "ClickTime" "integer"
Duration of the mouse click generated by tapping.
Try lowering the value of MaxTapTime (touch and release time) from 180 to, say, 90. It will make yr pad more sensitive to taps, hopefully helping the kernel discriminate between a quick tap and a change of finger during pointer movement. That will certainly have side effects, which you can gauge by referring to this.
If this does not give you satisfactory results, try to:
3) Turn off Synaptics Pressure Motion (294): 30, 160:
- Synaptics Pressure Motion: 32 bit, 2 values, min, max.
All the tools and documentation you need are referenced and demonstrated in this answer as well as in a previous one already cited by you.
NOTE: I am not sure anybody can help you anymore than that, as the solution is very much dependent on trial and error and yr personal taste. For that reason this type of question does not elicit that much interest. This is understandably important to you, but I am afraid that getting into such particulars and specifics may fall outside the scope of general interest.
Best Answer
Although xdotool is a more generic solution, compiz has a solution for this:
Install CompizConfig Settings Manager, go to the Scale plugin, Bindings tab and choose 'Initiate Windows Picker'. Choose any corner/edge to show all the windows.