Well, I need some help cause I like to play this sort of map:

30 girders all susppended in the air over the waters of death.
low gravity, all weapons, infinate ammo, 2x damage and walk fast.
Then, fight it out over the sea!

This type of game is fun, but takes like 30 minutes to set up.
Does anyone know how to save how the landscape is like so I can play the map instantly?
Or better: make a map like this?

Yes.
1: Use the search function on this forum to find a Worms3D level editor made my Alex (I think his name was Alex anyway). Although it's designed for Worms3D, it still works for Worms4 but without textures.
2: The all-weapons, infinite ammo scheme, called The Kitchen Sink, is unlocked when you beat everything else in the game.
3: 2x damage and Fast Walk are wormpot options, and have to be set up separately.

Does anybody even know how to use that Map Editor?

Does anybody even know how to use that Map Editor?
Considering that someone just posted a pack of 125 maps made using it in the Worms3D forum, I'm gonna go with 'yes'.

n00b Question: Is it compatible with W4? I kind of want the map he's describing, but it's a little different.

EDIT: I figured out the answer, textures just don't work.

Does that mean that I will be playing with plain models only??? The white models, or worse... THE GRIDLINES...

Does that mean that I will be playing with plain models only???
No, but it will mean that the texture of the models will be pretty much random. Because what might look like a grass texture in Worms3D might turn out to be a sand texture in Worms4.

So it's like plaid, you never know what it'll look like.