1: The Big Bang model actually describes the expansion of the Universe after the initial point. That does all follow the laws of thermodynamics. The initial moment itself, we have no idea what laws it might or might not follow, or even how to describe laws that it might follow.
2: It depends on precisely what you mean (more on this in a bit). But whatever happened right at the initial moment (if “happened” is even the right word), it’s not an ongoing process.
3: Energy that’s turned into heat is not destroyed. Heat is a form of energy. It’s not a very useful form of energy, but it is energy. I suppose you could talk about usefulness being destroyed when other forms of energy are converted to heat, and yes, that goes on all the time everywhere.
4: You mean, can “normal” matter be converted to dark matter, and vice-versa? Probably. In fact, I can think of at least one way to do so that would be certain to work. But it can’t be very easy, or we would see evidence of it happening.
5: In a sense, yes. Again, more on that in a bit.
6: We can’t completely rule out anything involving dark energy, since we know so little about it, but if anything, the reverse seems more likely (dark energy turning into “ordinary” matter), and it’s speculated that something much like that already happened long ago.
7: I’m not sure that I would speak of space being “created”, but we can certainly say that it’s expanded, and it could in principle contract. So far as we can tell, it (well, spacetime) is a thing in and of itself.
8: Again, it’s easier to say “expanded” or “contracted”, rather than “created” or “destroyed”. But yes, time can and does expand and/or contract, just as space does.
Now, onto the more detail I promised for a couple of questions. One of the laws of physics, and the First Law of Thermodynamics, is the law of conservation of energy. This law is, so far as we can tell, absolute, but it does not mean what most people think it means. It does not state that energy cannot be created or destroyed. What it actually states in a nutshell is that, if you have a box, and the energy content of the box changes, it’s because of energy flowing through the walls of the box (though of course, the actual Law is stated mathematically). Compare, for instance, to people: You can have a box containing some number of people, with no people going into or out of the box through the walls, and yet have the number of people in the box change, if they die or reproduce, so people are not conserved in this way.
Now, what does this state about the Universe as a whole? Not much, because the Universe is not a box. The Universe doesn’t have any walls, and it’s possible for something that might be defined (if you’re very careful about how you write your definitions) as “the energy content of the Universe” to change. For instance: You would expect that as the Universe expands, the density of energy in it would decrease. Specifically, if it expanded by a factor of 2 in all directions, you’d expect the density to go down by a factor of 8. And this does seem to happen, with matter. But the density of radiant energy (like light), while it does go down, goes down by a different factor. And dark energy (which seems to be most of the energy in the Universe) doesn’t change its density at all, no matter how space expands or contracts. So if space gets twice as big, and any given volume still contains the same amount of dark energy, one could say that dark energy is created.
Now, what I mentioned about dark energy maybe turning into other forms: When the Universe was very young, there was a lot more dark energy (or something that behaved very much like dark energy). How much more? Let’s just say that, however much more you’re thinking of, it was a lot more than that. This was an era that’s referred to as “inflation”, and it was characterized by extremely rapid acceleration of expansion. But then it stopped. And the speculation is that the way that it stopped is that (almost) all of the dark energy converted into other forms, and that those other forms of energy eventually coalesced into, well, us (and everything else). Now, we don’t know why we still have any dark energy at all. Maybe what’s left is some different sort of stuff that won’t convert into other forms of energy (and we don’t know why there was so little of that kind of stuff, relative to the other kinds). Maybe what’s left is the same kind of stuff (and we don’t know why it didn’t convert at the same time that the rest of it did). Maybe it will eventually convert to other kinds of energy, for one reason or another. This is just one of the many things we don’t know about dark energy.