Your GC is correct. he can submit the simple drawings or plan drawings to the city for permits. even a homeowner could submit a drawing for permit approval.

As for the structure, unless you're dealing w/second story or need heavier footings, a structural engineer isn't necessarily needed. (for example, you really don't need one if you want to remove one wall between kitchen and dining. If there is no floor above it and it's a simple removal, the GC can take care of that. ) But since you're doing a lot more that is impacting load bearing, then he is right to hire the engineer.

Are you adding square footage?

your GC sounds like he's on top of everything, even knowing his limits on design.

Thanks Beth. We are not adding any SF, just redistributing (Ha!).

then the engineer is a good choice on his part. It shows he knows his limitations and wants to pass inspection w/o any hold ups.