Sorry for my very delayed response to this, all.
I have to admit that I was hoping for more responses like "Oh, it totally changes at 4.5 and then they are delightful and hardly ask questions at all", but that's probably too much to ask. Hah.
I'm periodically still having a tough time with the "MORE INPUT! MORE INPUT!" thing, and coping as best I can. I've resorted to telling him plainly when I need quiet time so I can keep being patient and nice, because I think I tend to get overwhelmed by all the talking and questions, and go way beyond the boundary I need to enforce for my own sanity. So I'm working on that a little bit.
I also get the impression that he's in the process of teaching himself to read, which is probably very stimulating to his little brain. Part of me hopes that when he learns to read a bit, he won't need as much constant input from me - but that's probably awfully optimistic!
