Another, related Machiavellian tactic is, when starting a relationship that you suspect will be highly valuable to you, is to have an argument with them as soon as possible, and then to patch things up with a (sincere!) apology. I'm not suggesting to go out of your way to start a quarrel, more that it's both a valuable data point as to how they handle problems (as most relationships will have patchy moments) and it's also a good signal to them that you value them highly enough to go through a proper apology.
They are perils of assuming that hydrogen is the future, or perils of basing your energy needs on it - i.e. the peril is not in the hydrogen, it's in making plans involving it
Somatic cells are generally dead ends evolutionary. Your toe cells aren't going to do much reproducing. Also, mitochondial (or in general organellar) DNA is split between the actual mitochondria and the cells containing them. Biology is fun!
The argument for mitochondria is that they cause the cell environment to be more toxic (what with them being the cell's powerhouse). This in turn is going to provide a lot of selection pressure. In the same way e.g. global warming is causing a lot of selection pressure.
Runaway sexual selection has limits. This is also sort of the point. If you can carry around massive breasts, tails, noses or whatever and still be very prosperous, that means you're good. Where "prosper" can mean running away from lions if you're an antelope, or be the top of the village pecking order if you're a human. Like a short pro basketball player. If they're short, but still at a pro level, that's someone you want on your team. This is known as the handicap principle, and can be explained via signaling mechanisms.
The number of generations controls how long your experiment lasts. The longer (or more generations), the more drift you have, so the more likely for a given gene (or in this case - genders number) to take over. This effect will be weaker in larger populations, but unless you have an infinite population, given enough time (or generations), you'll end up with the 2 sexes (except for fungi, of course, as always). Eukaryotes first appeared 2.2 billion years ago. For comparison, the Cambrian explosion, with the first complex life, was only ~500 million years ago. That's a lot of time (or generations) for things to stabilize.
There are multiple mating types around. Mammals have the XY/XX chromosome thing going. Birds have a different chromosome set (denoted as ZW/ZZ). Some families use egg temperature to determine sex. Some fish have one male, and if it disappears, the next ranking individual becomes the male. Insects also have totally different mechanisms. But there are usually only the two sexes (apart from fungi), probably for the efficiency reasons outlined in the OP.
My understanding is pretty much what you said - when the going is good, then go asexual (e.g. strawberry runners, grasses or Asian knotweed), but also try for seeds, There are a couple of species of plants that have lost the ability for sexual reproduction, but I can't recall them right now. That being said, various plants used by humans can be pretty much exclusively reproduced asexually and so have lost the ability for sexual reproduction, specifically because they have very stable environments. The obvious examples are seedless fruits (bananas, grapes), but ginger and garlic are interesting plants that have been propagated from cuttings or bulbs for thousands of years and so lost the ability to produce seeds (with the normal caveats).
Aphids are also an interesting example, where the previous year's eggs hatch in the spring as females, which then clone themselves as fast as possible - when there's too many of them they will create clones with wings, and when autumn comes around, they will create male clones to then go through the normal sexual reproductive route. Which is also an example of the stable/unstable environment issues you mentioned.
This depends on the size and distances involved, but it's a good intuition. You need a mechanism to generate the pressure differentials, which can be an issue in very small organisms, which can be an issue.
Small and sedentary organisms tend to use chemical gradients (i.e. smell), but anything bigger than a mouse (and quite a few smaller things) usually has some kind of sound signals, which are really good for quick notifications in a radius around you, regardless of the light level (so you can pretty much always use it). Also, depending on the medium, sound can travel really far - like whales which communicate with each other over thousands of miles, or elephants stomping to communicate with other elephants 20 miles away.
It's not just from https://aisafety.info/. It also uses Arbital, any posts from the alignment forum, LW, EA forum that seem relevant and have a minimum karma, a bunch of arXiv papers, and a couple of other sources. This is a a relatively up to date list of the sources used (it also contains the actual data).