... ないものは ...ない => is not entirely impossible N3
Ability
…の…ないの => thinking whether or not to do something... N2
Position, perspective
たものではない => Impossible N2
Evaluate
…からいいようなものの => It’s a good thing that… this time… N1
Criticize
というのなら => If say that N3
Speculation
~のなんのと => For example... N1
Demonstrate by example
…くらいの…しか…ない => Only… at low level N2
Limit, limit
…のも無理 (は) ない => It's natural for... N3
Evaluate
ものもV-ない => is not entirely impossible N4
Emphasize the negative meaning
ないものでもない/ないでもない => A is not completely impossible N1
Need/Requirements
(の) なら~がいい => if; in the case that ..., you should... N3
Invite and advise
ないものか => isn't there; can’t we…?; can’t I…? N2