Here's my take:

№1 What do you think the tree on the far left represents? Why is it in that particular spot on the painting?

That tree represents the left wing of American politics, which is also dying like the other trees.

№2 What about the black and dark structure on the middle and right? What does it represent and why there specifically?

It's really hard to make out structures. If you didn't pointed it out, I would have missed it. They are in the tornado.

The tornado represents a political storm, which has already formed. Some houses have been sucked into that tornado. Are these houses MAGA?

Trouble with tornados is they are difficult to predict their start, path, and finish. A very apt image.

№3 What about the three black/blue/yellow structures? What do they represent? Why so ambiguous looking?

Those I do not see at all.

Three trees have one golden leaf. I have no idea.