Sorry, I do not know the answer to your first question, I only know about the published criteria for direct admit to Kelley.
As far as how hard it is to transfer to Kelley after getting into IU, that’s also hard to answer. The current requirements to gain standard admission to Kelley can be found at http://kelley.iu.edu/Ugrad/Admissions/CurrentIU/page39067.html
There are lots of really good posts under Indiana University - Bloomington that give advice and strategies for gaining standard admission, like what classes to avoid. Search on “standard admit”. You basically will need all A’s and B’s your freshman year. How hard that is will be a combination of how hard you apply yourself to your studies, what classes you choose, and maybe some luck (getting easier professors?). Someone on another thread said he thought about half of the students who apply get standard admission, but he admitted that was not backed up by fact.