なさる => to do (honorific) N4
させてあげる => (Allow) N4
Allow
てくださる => to give N4
Benefit
お…くださる => Please do ~ (honorific) N3
Respectful, humble
させてくれる => Let me... N4
Allow
[事「こと」]だ => A is necessary/good (offering advice/suggestion) N3
Needs, Requirement
~ さて...てみると => Until ... then, ... then... N1
Time
[事「こと」]ができる => Be able to A; can do A, Can A; be possible to A; N4
Causative, Passive, Volitional
事と次第によって => Depending on the progress of the situation N2
How to say the beginning
てさしあげる => Do for N4
Give and take advice
... とされている => to be considered as (A) N1
Consider it
てさしあげる => to do something for somebody N4
Respectful, humble