If you go to Options -> Interface then there are tons of options. Appearance is the first one. The nicest themes cost a little platinum, but the free ones work for most people.
The icons are annotated when they first appear, the game expects that you learn them over time I suppose.
I do agree that critical information should be front and center, but there is a lot of argumentation about what is critical information, with information that is critical to one warframe being irrelevant on others.