Basically... all of them. Here is a prime example Soy. Now humans worked on altering Soy so it would mature at a slightly different amount of daylight and whammo Brazil became a massive Soy exporter when prior it couldn't grow Soy in most of the country.

The short answer is no. Soace isn't actually 'empty' and the answer has nothing to do with cosmic radiation. It has to do with kinetic energy. Particles will strike your 'object' and impart kinetic energy which will generate 'heat' due to friction basically. 'Barrier' levels are hard to meet. I.E. you need a lot if energy to heat water from 1 degree Celsius to 99 degrees Celsius. You need a lot more to actually make water boil and reach 100.

Don't know the math well enough to say definitively, but my gut says nearly impossible. The gravitational 'turbulence' would seem to guarantee you wouldn't get the spherical compression pattern to create a singularity.

It would vary pretty widely on at least two factors.

1.) Ratio of relevant mass i.e. a white dwarf flung away from a multi-stellar system runs into a massive O-type Giant star (say 150+ stellar masses). Likely it never actually collides. The incredible difference in their gravitational fields would tend to force the incoming dwarf into a decaying orbit rather than a 'whammo'. Then the massive star would just 'eat' the smaller one.

2.) Angle of the collision. A good example of this is Luna (our moon) vs an asteroid belt or ring formation around a planet. If two stars of approximately equal size hit head on? Yeah whether the 'explosion' destroyed that solar syatem or not the gravitic disruptions would almost certainly either fling off the planetary bodies as rogues or would suck them in and vaporize them.

Because it never receives any reflected light from Earth, thus from our perpsective it is the 'dark side'.

Not always and you know that's true if you just think about it. Have you ever met someone with enormous wrists and hands for their size? The body-type really doesn't matter there.

The short answer is yes. You've seen it yourself if you think about it. Ever notice an adult with extremely 'fine boned ' hands, wrists, and feet? Then people with a wrist it would take both your hands to wrap around and a fist the size of your skull? There is no real fat or musculature in those areas, thus that IS a difference in skeletal size and density. Now that term is usually just mis-used to describe someone overweight.

The short answer? Viral load. The number of viruses you are initially exposed to matters a LOT to how quickly and how severely your symptoms occur. You just 'caught a whiff' and the viral colony started small. Then it started to breed. Reached 'virulency threshhold' and voila you're 'suddenly' sick as a dog.