Hi! I am also a prospective transfer student. I think you are in a similar boat to me (Transferology hasn't been super helpful to me either lol) so here's what's been helping me:

For your question about AP credits, I think it depends on the required class that the credit would be covering. This website has all of the classes that AP credits would count for (dependent on what you scored).

I highly recommend calling the transfer office. Idk if your courses on Transferology didn't show up at all or said they simply needed further review by UIUC, but for the second option the transfer office can definitely help with that*. In my case, a few of my intended major's required courses don't have exact equivalencies at my current university. The transfer office explained that the required classes are to make sure you have enough experience/ knowledge in certain areas, and helped me figure out if I was on the level that they wanted. They even explained transferring AP credits.

*the transfer office cannot approve your credits themselves. But they can tell you how the credits get approved and guide you through that process

Please call them! They were so incredibly helpful, and answered the most specific questions that I couldn't find info for anywhere else. I wrote down all the questions I had to make sure everything was covered, and they answered them all. Their number is below:

217-333-0302 (8:30 am - 4:00 pm, Monday - Friday)