Unlimited plans are for the psychological benefits of not having to pay attention to use. Personally I'm pay-as-you-go because I can only afford a few dollars a month, but that makes it a lot more stressful for me when someone keeps wrong-number-texting me and won't believe it costing me 10 cents a text, or when I have to decide whether it's worth starting a conversation that could cost a bit. People will pay extra to not have to worry, and that's legitimate and understandable.

As a pedestrian, you're supposed to be walking opposite traffic. If cars are coming up behind you instead of approaching in front of you, you're doing it wrong.

Why should silence be a goal?

Billions of people actually have to live on those streets you drive down, and the noise affects their lives and traps them inside and causes an obesity epidemic.

Both blind and sighted people can use crosswalks. And if car engines were silent, you'd start to be able to hear the sound of the tires in the same way you can hear human footsteps when there aren't a bunch of noisy cars around. There is danger during the period when there are enough noisy cars to drown out the quiet ones and few enough quiet ones that the public doesn't expect them, but silence should certainly be the long term goal.

Particles are not all touching each other, so the distance between them is necessarily considered empty. The space between a nucleus and electrons in an atom, the space between different atoms, etc. These spaces have field energy but no particles so they're empty.

Adobe and MS Office are things people buy. Windows comes with the computer for the vast majority of people (hidden cost), so they'll react badly to suddenly discovering they have to pay for it.

I see a market for fake cigarettes that expel a realistic-smelling smoke-like vapor without any health downsides, allowing everyone to take smoke breaks.

It's also worth noting that it's not until fairly recent times that a significant number of people could afford to eat out at restaurants regularly. It may be that people who ate out regularly were always fat, but there weren't many of them. Portion size increase is almost certainly a factor as well, but perhaps a less important one than eating out in the first place.

When someone is sick and needs to buy antibiotics, they do not research the environmental practices of the companies they can buy it from. People buy blind. Doing nice things that they'd approve of if they knew doesn't help sell anything.

AIDS is a significant lifespan factor in some countries as well.

In Africa (and previously everywhere), people tend to live in large extended families where there's plenty of people around to share the responsibility of taking care of the old and their dementia. Plus of course they have no money to involve a doctor.

I thought that most Americans committed 3 felonies a day.

If you thought that, it's because you never took a minute to investigate whether it was true or what the source of the lie was.

that fails to account for the fact that children out by themselves are a much rarer sight now, and are seen as an oddity, not commonplace.

I see children out by themselves every single day, be it walking home from school or just playing. Is there a certain demographic or region where it's rare?

The first stage of a rocket is never going to Mars, or even to orbit. They may need something different on a third stage of a Mars rocket, but that's no reason not to keep the first stage simple.

The French got to start over a few times after failed experiments.

Sub-orbital satellite flights with 5 minutes of weightlessness aren't going to bring much internet, so it's safe to say the satellites are not going up on Virgin's vehicle.

but as satellite communications typically suffer horrendous lag, Skype won't be a viable alternative to a mobile phone (en_US: cell phone), and the local infrastructure can continue to develop on the back of voice calls.

The notorious lag is geosynchronous satellites, whereas this is low earth orbit satellites (which you need a lot more of to make it work, but will give you much better ping times).