Betelgeuse, I'm afraid I must disagree with all of the points you made!
You do not necessarily need a series of texts in order to learn mathematics. It is true that certain concepts won't make sense unless you've learned other concepts, but that doesn't apply to everything. And anyway, it doesn't have to be seen as a problem. You don't have to prevent a child from jumping around through all of mathematics as it takes his fancy. Gaps in understanding are no more to be feared than unexplored areas of his neighbourhood. When he has reason to go there, he'll fill them in. You don't have to learn about recursion, or even algebra, before playing around with fractals. There are things you can do with them even without fully understanding them. Through an interest in fractals you may be motivated to go learn about recursion or algebra in order to enjoy fractals better. This is an excellent way of learning, better than slogging through algebra because it is what comes next in the textbook and somebody has told you that you may not try anything else until you've mastered algebra. Nobody makes a would-be footballer do endless ball handling drills without ever letting him onto the pitch to play an actual game and become motivated to want to improve his ball handling skills with drills.
If you have found that you go rusty after being away from mathematics for more than two weeks, then that is because you did not understand the concept in the first place. Mathematical understanding is not such a fragile thing as you describe! People studying maths at university often have more than two weeks between terms, and I've never known anyone who felt compelled to study constantly in order not to go rusty. Nor is there any minimum amount of time which must be spent on maths every day. You're making this sound like a huge chore, whereas it should be a joy. If it isn't fun then it isn't a good use of Voidka's son's time at this moment, especially since he is bright and it sounds like he is not behind the rest of his class. He should do exactly as much as he wants to do, when he wants to do it. He will make great progress if he is interested.
After a strong early interest, my daughter studied no mathematics whatsoever between the ages of five and nine. Then she swallowed down huge gulps of it for a couple of months. Then she left it. She does not appear to have forgotten any of the concepts she had mastered earlier.
Using physical representations can be fun. Many people love it and some find it much easier to get hold of ideas that way. However, it is not essential for everyone. Many mathematicians have an excellent imagination and do it all in their heads, perhaps with a few sketches when things get tricky. By all means, the boy should have the chance to make things if that is what he likes to do, and you've listed some fantastic ideas above. But if he doesn't want to do those things, he'll be fine without them.
I'm sorry to come down on you like a tonne of bricks. It's just that I love mathematics and I feel that many people are put off by an overly prescriptive approach to it, such as is followed in most schools. Ask a mathematician how to learn maths, and in what order, and I am sure you will invariably get the answer: follow your curiosity. Sadly, it is exceptionally rare for a mathematician to teach maths in a school.