[bluong1]

some people say you should not "ride the clutch" or keep it in all the way while you are idle, because this can wear it out. I don't see how that is possible if you are stopped and idling and have the clutch pedal down all the way ... it is not anywhere near connecting to the flywheel if it the clutch is fully engaged, right? You could sit there forever and not "wear it out", correct?

- "Ride the clutch" is different that what you describe. Ride the clutch is taking unecessary long time to disengage/engage the clutch. This will wear the clutch plate.

- Sitting at the stop with your feet pressing the clutch can't wear the clutch plate (the plate that connects to the fly wheel by friction) as you correctly pointed out, however it will wear the release bearing (that's the part that presses against the pressure plate and "releases" the disc). But it's OK to do it now and then (e.g. when you know and anticipate the green light)

 

[bluong1]

never go around curve with the clutch pressed down. You should always downshift before the corner. While being in the corner, the engine compression should be fully used to modulate the speed, because the brake applies an even force on the outer and inner wheels, and this is not a good thing during cornering. In addition, you are ready to accelerate without jerking when exit the corner.