[使「し」][役「えき」] => Coercive, permission, allow, make N4
Causative, Passive, Volitional
[使「し」][役「えき」][受「う」]け[身「み」] => Imperative N4
Causative, Passive, Volitional
[要「よう」]するに => A. In short/put simply, B N2
Adjectival, Descriptions
[必要「ひつよう」]はない => It is not necessary for A to be done N2
Needs, Requirements