needed, crucial, relevant
Another word for simpler is easier. You could also use a phrase such as 'easier to understand', or just basic.
Well, sweetheart, another word for "easier" would be "simpler." It's like saying "I'd rather eat a slice of cake than run a marathon." Simple as that.
valuable
Big is a synonym for important.
Critical
essential
Pompous or ego. Those words mean self importance.
"Imperative" or "Important" is another word for essential or compulsory.
vital Imperative
Important
Very Important Person
Significant or major.