Thx Mark.
If anyone finds this post via a search later - here is what I found out.
The Floodway is apparently classified the same as the Flood Area - AE so insurance is required and there are also construction limits requiring you work with FEMA/Structural engineers for all building or remodeling or get a permit to go ahead within them in some cases.
Insurance costs are entirely dependent on the elevation certificate which I would have needed to commission myself since seller didn’t even know they were in a flood plain OR I could have negotiated to have her commission the survey. My insurance agent said in some extreme circumstances it is possible no one would flood insure the property and then it would be impossible to bank finance the deal. Also if the property was grandfathered in or at a compliant elevation once the survey was done and a certificate issued then the flood insurance could be under 1k but it had the potential to be very very expensive (many thousands) or as previously mentioned even uninsurable Zone and Floodway AE had roughly 26% or 1 in 4 chance of flooding over the lifetime of the mortgage
I walked away from the deal and informed the seller so she is prepared for the next buyer.