It's not always easy.
Have you ever seen how race maps ([DM]) maps look like?Full of decoration and track,and it's hard to make it look good.
That depends on person's imagination.
Not only imagination tho there are a lot of stuffs like loop programs and more
Why there is no mapping team? That's team can help players who need to know about mapping like scripting team that's help players who want to learn lua ect...
You using the right version have you try to restart mta or re-install it?
There are some objects you can't remove them by map editor can you take ss for what happens for you?