So far the only evidence I have that inflation theory is about the creation of the universe rather than its rapid expansion is your statements. Literally every link, from every site and physicist and cosmologist I have seen in this thread, including those provided by and quoted by you, say that inflation is about the rapid expansion of the universe at its beginning, either just before or just after the Big Bang, depending on how one defines it.
Here's Alan Guth, the man who proposed inflationary theory:
"Inflationary theory itself is a twist on the conventional Big Bang theory."
"The basic idea behind inflation is that a repulsive form of gravity caused the universe to expand."
"It explains not only what caused the universe to expand, but also the origin of essentially all the matter in the universe at the same time. I qualify that with the word "essentially" because in a typical version of the theory inflation needs about a gram's worth of matter to start. So, inflation is not quite a theory of the ultimate beginning, but it is a theory of evolution that explains essentially everything that we see around us, starting from almost nothing.."
THE INFLATIONARY UNIVERSE | Edge.org
Yes, before this thread I had heard of inflation. I've certainly looked deeper into it here than I had previously, though.
What do you mean what is the most important part of inflation? Important to anyone learning about it, important to those who ascribe to it, fundamental to the concept? And considering the man who came up with the idea says that "in a typical version of the theory inflation needs about a gram's worth of matter to start," does that qualify as the creation you are talking about? This seems a bit like a "Have you stopped beating your wife?" question.