Causality is implied by LOT and conservation. I would frame as saying entropy is applied in diferent forms, not redefined.
There is no concept of causality in modern physics, there are only interactions which follow specific patterns. Causality, as we experience it, is an emergent phenomenon at the macroscopic level associated with the arrow of time, and the number of internally rearranged states that a system can exist in after a certain point in time relative to its state just prior to that point. There is nothing in the laws of physics that prevents the creamer and the coffee separating out into creamer and coffee after they have been mixed in a cup. But the number of possible states in which the coffee and the creamer molecules are separated out is much, much, much smaller than the number of states in which they are mixed together into a more-or-less homogeneous mass. It is simply a matter of probability, and precisely how entropy works.
To me conceptually entropy represents energy in the system not available to do work in the system .
No. The entropy of a system is the number of possible states with internal rearrangements of its constituents that the system can exist in without fundamentally changing its external, macroscopic attributes. That is how Boltzmann defined it in the late 19th century, and it is strange that you do not seem to know this, given how frequently you bring up thermodynamics. In the example above, the cup of coffee and creamer will continue to remain mixed because the probability of the system achieving a state where the coffee and creamer are separated out is very, very, very small. That is entropy in a nutshell. Again, there is no cause and effect driving the behavior of the mixture, it is just statistical probability.
Take a look at steam tables. All done in software now. Steam tables were used to determine how much steam at a given pressure was needed to do work in a system
And that is the root of the problem - your belief that one can make definitive proclamations about something as complex and poorly understood as the physics of the early universe armed solely with a knowledge of steam tables. You cannot understand the physics of the early state of the universe using the concepts used to derive steam tables. Classical mechanics cannot describe the behavior of such a system. Even relativistic mechanics (Einstein's theories of special and general relativity) cannot define the behavior of such a system at a time when the universe was very, very young (less than 10^(-34) seconds after the so-called Big Bang event). To make definitive proclamations regarding what is or is not possible, based solely on your somewhat fuzzy knowledge of steam tables, Newton, Maxwell and Boltzmann is foolish.
Something from nothing is very much permissible under the rules of modern physics. We have a lot of experimental evidence to demonstrate that such things happen all the time, that a majority of the mass of your body is derived from short lived virtual particles. And that this can happen WITHOUT violating the known laws of thermodynamics that you are so fond of using as a shield. Consider the following: We know that the universe is expanding, and new space is being created out of nothing all the time. Moreover, this new space is not empty, it has vacuum energy. So not only do we end up with new space from nothing, we also seemingly end up with new energy from nothing. Surely this must violate the laws of thermodynamics? It doesn't. Because as new space is created along with new energy, the separation between areas of matter/energy concentrations are increased, which causes a global decrease in the gravitational potential of the universe as a whole (the ability of the system to do work under the presence of gravitational gradients). This is the balance Hawking was talking about. In the first post in your other thread you quoted Hawking, and asserted that Hawking was making ridiculous claims without evidence. But you did not do the fucking work to read the book where Hawking explained what he was talking about, because you know all about steam tables, and steam tables are all you need to know to understand the fucking universe. You probably don't even understand what Hawking and others are talking about when they use the word "nothing" in this specific context (nonexistence of matter/energy versus nonexistence of spacetime itself).
I understand that I am unlikely to change your mind in this matter, and that you will make no effort to educate yourself on thw work done over the last 100 years. And thats ok. You can add me to your ignore list as you have done others, so you don't have to listen to the voices telling you that you are misinformed.