need help with multiple devices and apple id

Between my husband and myself, we have two Iphones, two Ipads, and one Imac. I back all of them up on my Imac using ONE iTunes account....we prefer not use Icloud, and I think that helps keep the information on each device relatively separate from each other...no overlaps with contacts and calendars. We have one APPLE id and password, that we use for Itunes and the App Store. We just got the Iphone 6 for my husband, and it keeps asking him to enter his Icloud PW.(his recognized user name is his PRIMARY email address)...which presumably he does not have, nor does he need (or maybe he does I need some real guidance on that). To keep this from making him crazy can I just delete his Icloud account, which again presumably, was created automatically with the new Iphone 6 set up??

Similarly, I need to use FIND my Phone (etc), and HIS devices are not in MY listed devices....is this because he NEEDS his own APPLE ID, or is there a way to add his devices to my list of devices within the APP....I thought because we share the Itunes account they should all be in MY devices.

Can someone help me make sense of this?

THANKS!!