Honestly, I woulnd't discuss the TV stand thing with him that much. The first time you go in the room with him for the day I'd remind him he's not supposed to go on it. The first time he gets on it I'd say, "You need to get down from there - you can get down yourself or I will help you." Then if he doesn't get down, I'd lift him down off without saying anything. Then if he climbs on it again, I'd just walk over and remove him from it, saying in a serious, flat, but almost bored tone, "That's dangerous, you're not to climb on it." and do it every.single.time. Even if you have to do it 100 times the first day, it will eventually sink in. I forget what the object was with my daughter, but I remember the first day I had to move her 26 times. It happened less the next day, and wasn't an issue after a few more days. While I agree with making environments kid friendly and not museums, I also believe that kids over 3 are definitely capable of learning that there are *some* things that are off limits. If he was 2, I'd say move the TV. But not at 4.
I'm sorry your mom isn't speaking to you, that's really on her and not you at all. Previous posters have given good advice on howto address her regarding why you're parentign differently. I might just add that maybe you could say to her something like, "I realize that I've turned out OK with the way you parented me. But kids can also turn out OK being parented different ways, and I've decided to try this different way." The way I see it - even if your kid turns out OK if you hit them, they also turn out OK if you don't hit them. So why on earth would you choose the method where you hit them? I think the problem is that a lot of people see no punishment (as in arbitrary punishment) as "doing nothing" - but that's simply not true. Stopping my kid from doing something hurtful or destructive, taking an item away from them when they're damaging it, leaving a place when they're not able to handle it, not allowing them to run amok, that IS doing something and they are learning something, which is, "you need to consider others when you do things"....it's just NOT arbitrarily adding something on top of that to drive the lesson home....which usually just ends up distracting from whatever lesson you were trying to teach and just makes them think about hating whatever punishment it was that you put on them.
re: learning about the harshness of the world. Kids aren't dumb. THey figure out very quickly what is OK in some situations isn't OK in others. They will learn the ways of the world without you having to do much of anything, once they start interacting with people more in public. I figure I want my house to be a soft, safe place for them to fall and regroup, a haven from the world, not just another place where nobody is looking out for them.
I am on the stricter/firmer end of GD, and do use logical consequences sometimes. While that's not the UP or consensual model, it still does fall within the realm of GD.