Another comment regarding the click and drag behavior.

One thing I would definitely expect a recent migrant to apple trackpads to experience as negative would be "force click". The apple trackpads sense force in some analogue way and if you push hard enough you can activate another action called force click. It's ridiculously easy to activate on accident when holding click while dragging -- but this "feature" can be turned off (and probably should be for most people I'd wager).

I've never tried using the middle finger for dragging -- seems awkward but i'll give it a try ... won't that activate the two finger drag operation?