How to improve the oven has been known for ages.
The problem is that it's costly to do right, especially if the oven needs to actually be a reliable oven and last at least 10 years daily use.
For example 'optical sensors can be placed in the oven to ...'

How do you keep these clean after the four hundredth time they're spattered with grease at 250C and it's burned on to a nice black film.
How do you determine what the food is, and what the surrounding dish is in order to pick what needs to be browned.

The 'right' way to do this would be with thermal IR cameras.
Unfortunately, this raises even more cost issues.

Fulffffffffffffffffffffffffffeh!

It getting into guts is a different problem.
Plastic microbeads are _excellent_ at absorbing many pollutants onto their surfaces.
When this is eaten in quantity, this can be a really efficient way for those pollutants to get into the fish - and hence into the food-chain.

Woo - apple fixes slow internet and data caps - magic!

The difference is that few would argue that going hunting by connecting your gun to a couple of $9 servos, and operating it over a glitchy radio link where you have a tiny field of view through a bad camera, and it may randomly go off if you lose radio is a sane thing to do.

Cars exist, right? Foldable bikes exist, and there are quite a number of them out there.
Buy my foldable 400MPH 400 miles to the gallon car which folds up into a suitcase, only $1K.

$500K is not enough to develop custom silicon for the task. They're using someone elses chip.
The format can't capture enough power, due to unfortunate laws of physics to do bluetooth pairing.
Batteryless NFC RFID tags work with a comparatively huge field to power them. (millions of times as
strong as a nearby wifi router)

Not only supersonic - it seems likely that they'll perform quite adequately even down to the ~80m/s that it hits while freefalling down to a landing.

I'm not sure about added weight.
Certainly, it's added weight, if the stage is not intended to be recovered.
However, the extra control authority right down to the point you need to light the main engine to start the 3-4G burn means that you may gain back the
mass in less fuel needed both for the main engines and attitude control systems.

The test stage shown in the video above is a test vehicle used to test - amongst other things the aerodynamic surfaces.
The prior launch of falcon 9 had a first stage which came down in the sea, at a low enough velocity that if it was on land, it would have landed safely.
The aerosurfaces tested yesterday will help enormously in fine control and reduce the need for lighting the engine during some parts of the descent or fuel for vernier engines on the proper full sized and weight stage.

Not having a formal qualification does not - in other than the strict legal sense that is almost meaningless make you not an engineer.
Being a civil engineer - for example - would not particularly help developing rockets.

Spending ones own time to gain an understanding of the mechanics of rocketry well enough to be able to do broad conceptual design with somewhat realistic numbers that you hand off to others to check and implement is quite possible.
  This is the normal role of a lead engineer in a project.

In 12 years, Musk has gone from having no involvement in space to actually having a company that's designed and flown several rockets.
Actually having a first stage that is reusable (the first stage of the last rocket launched hit the ocean slow enough that if it'd have had legs, and been on land, it'd have been reusable with little more than refueling)
Having actual customers for a new rocket which exceeds all current launchers lift capacity is also notable.
Mars is a hell of a stretch, yes. But he's already come a long way.

The costs for mars are generally costed without assuming renewable launch. If this can be gotten working, a lot of the costs go down dramatically.

Quite - it's not getting very very cheap.

Can it get cheaper than some things people already put on roofs - especially when you take into account 30 year life with
no maintainance - quite possible.

Because unfortunately, an IPO for the general public means that unfortunate things happen.
You lose signifcant control of your company - possibly totally.
Musk developed Falcon Heavy - with essentially no market.
The Raptor engine currently in development has no market.
The requirement for reusability is reasonable from a long-term perspective.

You can't - as I understand it - legally IPO to only those sharing your vision. You are going
to get pension funds and hedge funds and ... purchasing slices of your company to diversify their
portfolios.
These may then not want you to go spending money on wild unprofitable in the next 10 years crap, but
to make next years dividend larger.

My favourite tweet of all time is from Musk.
'No near term plans to IPO @SpaceX. Only possible in very long term when Mars Colonial Transporter is flying regularly.'

Well - one - sure.
The largest players in the market are at the moment shipping a gigawatt a quarter or so.
Ten gigawatts a year would make them the largest in the world by a comfortable margin.
And likely depress the price to well below $.50/W.
If they can get the price well under this - say $.25/W - then solar becomes economic in a lot
more places.
At that price, I'm buying 6kW or so.
At $.25/W, that is a price of $50/m^2.
This is in the range where it's sort-of-comparable with other roof claddings.

You really have no clue.
In much of the 'third world' - phones - dumbphones are revolutionizing banking, and doing things to enable farmers to get higher prices for stuff at market, as well as microinvestment.
http://www.cnbc.com/id/1011804...
Firefox are launching a $25 phone. Is it a good nice internet access device - no.
But it will render wikipedia (for example) and let someone track weather forecasts, and do email and essentially everything the internet was when you had a 9600 modem.
(neglecting for the moment that it won't be able to connect to the above satellites - but in several years it's plausible for the same price).
$25 is a lot of money for someone earning a dollar a day.
But, it is much less expensive than the cost of schooling for a year for a child.