Wow, that sounds horrible. Very glad I don't live somewhere with an HOA. Sounds like insanity. You can't even plant a tree without their approval? Can't have a single weed? What do they do? Do you get fined?
The reason for the rules about landscaping and large trees is simple: They don't want trees planted in areas that could impact another home. We've planted four trees. All we had to do was submit a simple form. Same thing with the kids' playset. We had to submit our plans for approval, but it was really easy. I don't want to live next door to someone with a rusted out metal swing set, trampoline, or dirty above ground pool. A single weed wouldn't get you fined. An unkept weedy lawn or garden would.
And yes. They can fine you. Usually you get a written note asking that you take care of a specific issue. For example, our neighbor got a note a couple of weeks ago requesting that they repaint their mailbox. They give you plenty of time to comply. If you don't, they'll send another note asking again that you take care of the issue. Next, you get a letter threatening a fine. And they can fine you for every day you are out of compliance. Finally, if you don't fix the problem and pay the fines, they can put a lien on your home.
The thing about HOAs is this: They are not for everyone. When you buy in an HOA community, you sign a contract agreeing to the covenants. No one has to buy in an HOA community. I love the fact that our neighborhood is always clean. I love that my neighbors' lawns are well taken care of. I also love the amenities that come with living in the neighborhood. My kids practically live at the pool during the summer.
Again, HOAs are certainly not for everyone. I can understand why some would hate the restrictions. But I like knowing that my property value is protected by the covenants. I would hate to try to sell a house next to a house with a junky yard.