All the OP's points mentioned are correct, and if all the points are actually done well there is no problem.
However, the problem with the points mentioned by the OP is that there are no points of important obligations that the wife must carry out in taking care of the household, husband, children and other important needs. And if these points are implemented along with the points mentioned by OP, then overall it will be safe. And I'm just afraid that everything won't go well, or maybe there are some wifely obligations that have been neglected.
And I personally would forbid my wife from gambling, and I have no problem with her gambling responsibly, having fun and so on. And I'm worried that my wife will neglect some of her work or obligations and also be a bad example for the children.
It's not just about obligations or responsibilities not being fulfilled or taken care of, but it's about the trust that is being broken. When you are in a relationship, especially if it's a marriage, you would expect your partner to share everything with you, and by everything I mean every single thing that they do or happens or whatever else that one can think of, and if one day, all of a sudden, you come to know that she has been secretly doing something without telling you, how would that feel? Ask yourself.
Most of the time, we hide things from others because we think those things are not for them to know as they will either get angry, not allow us, or because what we are doing isn't ethical. But if there is something so casual, like gambling for fun, as OP said she doesn't have intentions to get richness from it, so I don't see any point why she had to hide it from him in the first place.