It adjusts pretty I think it would fine
It doesn’t fall over unless one of the kids grabs the front of the basket.
I would think so. My niece who is over 4 feet had fun playing on it. It is going to vary from kid to kid. If you want something that he will enjoy for longer, I'd suggest finding a goal that adjusts up to 5 or 6 feet; but, I definitely think he'd have fun with this goal at his current age.
On the base of this basketball hoop (the black part) you can fill it with sand or whatever and that makes it very sturdy, other wise it might topple over depending on what age of kids are playing, I have a 15 month old grandson works perfect.
It was complete with the hand pump ,Very pleased with it.my kids love it ,very nice mini basketball ...