べき => should do; must do ~ N3
とでもいうべき => It must be said, it can be said N1
For example, simile
べきだ/べきではない => Should do A; Must do A, Should not do A; Must not do A N3
Needs, Requirement
たるべきもの => have the capacity to be a... N1
Of course
~てしかるべきだ      => should; appropriate; it is natural to do ~ N1
べつに => separately N2
Description
~べし => need, of course N1
Of course
べつだんの => particular; special N2
Description
なるべく => as much as possible N2
Limit, limit
~べくもない      => cannot possibly be ~. N1
に[比「くら」]べて/に[比「くら」]べ => When compared to A N3
Comparison, Exchange
てっきり...と思う => surely; certainly; without a doubt N3