"I imagine that Iceland's 200 mile fishing limit will be thrown open to French and Spanish vessels as our waters are."

I would think it highly likely that if the EU does want Iceland as a member, it would be possible to negotiate a special deal on this, since otherwise the likelihood of there being popular agreement in the referendum would be greatly reduced.

Fishing rights are central to Iceland in a way that they weren't seen as being by UK governments - otherwise I suspect they could have negotiated an exemption that gave more protection for local UK fisheries, perhaps in exchange for reduced rights to fish in other European waters.

The history of the destruction of the Newfoundland fisheries suggests that a link with a North American neighbour might not be too good an idea from this point of view.