に足りない/に足らない => cannot; not worthy; not worth doing ~ N1
に足る => worthy; worth doing N1
くらいの => Approximate~ N3
Emphasis on degree
どのくらい => how long N5
…くらいの…しか…ない => Only… at low level N2
Limit, limit
そのくせ => and yet; though; in spite of; despite ~ N3
Surprised
~のは…ぐらいのものだ => only (emphasis) N1
Limit
~くらいで      => only N1
ていく => ...lose, ...go (eliminate) N4
Status
にくい => difficult to do ~ N4
いつかの ... => Previously N4
Time
くらい/ぐらい => approximately, about, almost N5