1) Configurable in software. I have it right now in Ubuntu; I think it's the default settings, though perhaps not as noticeable and needs to be made more sensitive for others?

2) Probably configurable in software, but unnecessary. Double-tap-hold (where the second tap you don't lift your finger) means holding down the click from the first tap, so drag-and-drop works just fine with a single finger.

3) I tried a co-worker's Mac a few years ago out of curiosity after hearing so much about the touchpads, but something about the sensation bothers my skin so much I don't want to touch it for more than a few seconds. It's a similar revulsion I get to touching felt.