Ugh...I mean no offense, brotha, I understand the YECs' position, but I don't hold to any of it. At all.
I was trying to answer your question:
"Firstly though, when you say "a common creator would reuse designs", what info for that are you referring to, specifically?"
I thought you were asking where I got the idea that this was the creationist position. Perhaps I misunderstood your question.
So then, where's the problem? Evolution cannot possibly have been intelligently designed?
Intelligent design is widely held to be a process that runs counter to evolution. Intelligent design is described by the proponents of the idea as a non-natural process, a non-evolutionary process. One of the icons of Intelligent Design is Behe's "Irreducible Complexity" which Behe describes as not being evolved.
By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution. (p. 39)--Michael Behe, "Darwin's Black Box"
Theistic evolution may be closer to what you are trying to describe. If we were to ask the leading members of the Intelligent Design movement if Theistic Evolution is Intelligent Design, I would hazard a guess that 99% of htem would say no.
Just out of curiosity, has anyone ever suggested that perhaps the origin of life on this planet was initiated by an intelligent designer not God?
Some people have. In the end, you run into the problem of a universe with a finite 13.8 billion year history if we are going with more naturally derived intelligent designer. At some point, there had to be a First Designer, the first designer to come about without the aid of another designer.
As far as the sequence of events, you would need a second generation star with terrestrial planets. You would need billions of years of evolution for the First Designers. What little we know seems to suggest that we could be those First Designers.