が必要 => need; necessary N4
必要がある => Need/Need to N4
必ずしも~とは限らない => Not necessarily; not always N3
[必要「ひつよう」]はない => It is not necessary for A to be done N2
Needs, Requirements
にする => にする N4
すら/ですら => even ~ (with emphasis) N1
する => become ... N4
Situation, case
…すぎ ... => too much N4
Emphasis on degree
すぐ => Right now N5
Short period of time
すき => to like... N5
Ability
すら,ですら => Even A N1
(Not)only , (Not) even
いたします => to do (polite form of します) N4