Move your mouse out of the way! 
If you know the type and parameter of everything that exists in JS and node-red, then no.
However, if you are new to JS / node-red, I think it is invaluable. Even I cannot remember the parameters for many of the functions.
Have you seen the built in snippets? Try tying status or clone or getprop - then hit TAB.
If enter an incorrect type in a Node-RED function call, it tells you - look at this post and the follow up post below it.
However, if you are very stuck on having no help then sure, it can all be disabled - just add the necessary options in the settings.js file.
Its supposed to be. Its meant to show you a picturesque view where you can spot sections of code quickly (like a map). In fact it is called minimap and YES it can be switched off - just add the necessary options in the settings.js file.
