I was asked about age range when applying - they use that to prioritise applications I think, so if they have lots of 4-6 year olds coming through the system they prioritise the prospectives looking at that age range
Otherwise, for me the rest was not really looked at until and throughout the homestudy, and you can change your mind. In my mind, a main purpose of the homestudy for adopters is thinking through the kind of child you can parent best, and that can take months of thinking sometimes
The last time I was approved, we went through the checklist of potential issues and disabilties nearer the end than the beginning. Although that was just my agency, and others might do it sooner. It was over two sessions, because I marked out several issues that I wanted to research further in my own time before ticking the boxes
I did find that there wasn't much help at all in exploring certain issues. For instance, I wondered whether or not to tick 'yes' to HIV, Hepatitis, and other blood disorders, but I had to go research it on my own. Ditto other medical conditions like heart conditions. The SW just asked whether or not I was okay with it. I didn't know enough (in my mind) to commit to a yes, so I asked for more time, and it was a struggle to find out what I wanted to know. SW's aren't medically trained after all!! So I would expect some level of being on your own to work it out, although I was supported when discussing gender and age because the SW could advise more in those areas
It's also worth noting that now, adopters are blanket approved for all children. There is a recomendation for a certain age group, gender etc. But that is not mandatory, and you can adopt a child outside your recommendation. If you are approved for a 0-5 year old boy, you can still adopt a 7 year old boy. Sometimes (rarely) it happens!! So nothing is ever set in stone as it were. That is different from when I was approved, back then you were only approved for a certain type of child, so much less flexibility
I don't think you would be asked to be very specific until the middle-end of the homestudy. Although others might have had a different experience of course