The only subjects I have to make my almost 12-year-old twice-exceptional son do are math, handwriting and a little bit of piano practice--things that require good fine motor skills and he finds frustrating because he has motor dyspraxia. I ask him to do what would take me 30 minutes and he has all day to do it and sometimes he doesn't get it done. Part of the reason is frequent headaches, but there is also procrastination. He works on the 30 minutes of work that I assign a little at a time.
The rest of the time, on his own, he is usually on his computer with two monitors. On one screen he has a game or interesting Youtube videos and the other something interesting to read. He goes back and forth with this. He reads more than he plays. I know this because he likes to share all of the interesting things he learns with me. He loves taking quizzes that test his knowledge. Sometimes his dad's coworker plays a game of scrabble with him via the iPhone while he is doing the play game/reading thing. Oh yes, and then he often manages to listen to a show on either the Science, Discovery, or History channel and sometimes his adult sister, who is one of his best friends, is on speaker phone talking to him while they are both on the computer. He keeps in touch with his other friends (from the musical theater group) on Facebook throughout the day. He does enough typing on his mmorpg games and facebook that he managed to do 50 wpm with 1 error on a recent typing test. He taught himself to type and it is not the way I learned to type but it works for him. He says he learns better if I just leave him alone to do things his way.
When his headaches are really bad he is of course, lying on the couch doing nothing else but trying to keep from throwing up so I don't make him do anything, but he seems to make up for the time he is not feeling well.
At night he reads for hours. His favorite books are usually history related and he loves science and technology magazines. I recently bought him three books that he really likes--The Manga Guide to Electricity, The Manga Guide to Molecular Biology and the Manga Guide to Physics.
So I am not sure how to answer the question. I can't say 30 minutes (the amount of work I assign) and I am not sure what I could count of the things he does on his own as homeschooling. One of the games he plays online involves drawing something and the other person has to guess what he drew. That is all the "art" he is doing and we gave up on cursive for a while. It sounds like you have it all covered better than I do.