Do you have any other Nubus cards to make sure the nubus system is even working? 

Well, now that I think about it, the monitor wouldnt work either if it didnt... 

I suggest finding a copy of apple system profile, or something similar and see if the machine even sees the card. 

Need to make sure the machine knows the existence of the card via the DeclROM. Otherwise everything you are trying is moot. 

Ethernet is not showing up becuase the driver isnt loading. the driver not loading could be the result of the DeclROM not present/loaded, or the driver isnt correct for the card's IC.