New to Godot, I have some quick questions on the editor

Hello, as the title says, I am very new to Godot. I just finished following the 2D Game Tutorial, and I have a question on this part: https://github.com/godotengine/godot-demo-projects/blob/bf4d1038d623c355f3b49e613a2c9b686eebb312/2d/dodge_the_creeps/main.gd#L44

Basically, I had the idea to play around and try to give the mob a curved path, so I tried mob. in Godot's script editor looking for the completion engine to find me things similar to .linear_velocity only to find nothing, and also that linear_velocity didn't even show up as an autocomplete suggestion. No errors or warnings, and the code runs fine.

Question 1: Why does linear_velocity not get suggested? How can I change that, so I can have the editor help me learn the language and APIs?

Question 2: Unrelated to the above. I like Vim motions. Any suggestions on either:

• Installing a Godot plugin to get Vim bindings?
• Setting up Godot to use Neovim as my external editor?
• Just using Neovim externally to edit my GD scripts?

Just looking for thoughts on what people use and like.