~のは…ぐらいのものだ => only (emphasis) N1
Limit
... るとか ... るとか => それとも... または N4
Demonstrate by example
といえば…ぐらいのことだ => speaking of... just... N2
Respectful, humble
(か)とおもうと / (か)とおもったら => just when; no sooner than ~ N2
Simultaneously
と~と~どちら~か => Comparison N5
Compare
[事「こと」]だ => A is necessary/good (offering advice/suggestion) N3
Needs, Requirement
ぐらいのものだ => Only A N1
(Not)only , (Not) even
に[限「かぎ」]った[事「こと」]ではない => It's not limited to A, it's not only A N1
Degree/ Level/Amount
~てからというもの      => ever since ~ N1
~からとおもって => Because I think... N1
Base, base
いくら…からといっても => no matter how ~ N3
Evaluate
というのも…からだ => This is because… N2
Cause, reason