Maybe not courteous, but at least attentive. If you're driving a manual in stop and go, it's hard to be playing with a cellphone (not that it doesn't happen). You are being forced to spend some thought on the act of driving, which I think is a good thing.

Not really. An experienced manual driver can do it all with his/her eyes closed. It's just like the change from new driver to experienced driver.

One hand on the gear stick, one hand on the steering wheel, you shouldn't have a spare hand to use your phone. Or do you steer with your knees? :)

So you need to keep your hand on the stick while cruising on a long stretch of road or highway? That's where smartphone use becomes dangerous imo.

Just go to Italy or Argentina (100% manual) and you'll be disabused of that idea VERY quickly... that's the worst behaving traffic you'll ever see.

There are tons of inputs to consider here but driving a manual car does make you a bit more attentive to what your car is actually doing.

I realize you received a few of these comments already, but please also check out India if you think driving a manual improves safety and courtesy.

Manuals would probably shift driving away from the ignorant/nice/slow style of bad driving found in the southern US towards the attentive/aggressive style of bad driving found on the east coast. Definitely not more courteous, but probably more efficient and safer.

Definitely not. Check out any country that is not US for that. Not just Argentina or Brazil, but Europe too. Poland, for example.

(Personally I think everyone would be way more corteous and the roads would be safer if traffic laws were actually enforced. What I mean by that is e.g. ANPRs deployed pretty much everywhere, automatically fining you for speeding. The way most drivers I know treat traffic laws as mere suggestions is ridiculous.)