He doesn't need to eat, sleep, or breath in this state meaning that sure, inkmatas could fight him, however she's still able to get tired. So collector would win because of mortal limitations
However against creation itself it's not gonna do much damage
Again, only a being who can hit as hard as beldum can break the crystal, and the collector is pretty much made of it in this form. inkmatas mainly uses magic so I doubt she has that level of physical strength so if inkstone can't break it she doesn't really have any way to defeat the collector