From somebody who worked on touch intefraces: #1 could be hardware dependent. Most modern touchpads detects finger coordinates in firmware and send them to driver. Driver has not much to do to improve accuracy besides some high-level smoothing like Kalman filter. #2 is could be useful. Not that tools are completely lacking, but they can use some polish and unification. #3 is again hardware dependent. Most modern touchpads do palm detection in firmware. Nothing you can do to improve that. In the most cases it is not even possible to get a "raw" sensor reading.