"I'm intending to stay and critique these buggers pretty hard"

So said Steven Joyce. I hope he sticks to this. 

Explanations of policy concessions are now emerging and it appears National rejected those 'bridges too far'.

NZ First is also understood to have won concessions from Labour that National balked at, including work to progress a multi-billion dollar Northland port.
The deal will also cut property sales to foreigners - another policy National balked at, warning it would send an unfortunate message to our neighbours and be in breach of trade agreements.
Immigration was also crucial to NZ First's position - National rejected whole sale cuts. concerned about a labour shortage.

The last point mirrors my major concern with the new government.

New Zealand was built on immigration. I am an immigrant. The public services in particular - Health and Corrections I can personally attest to - are heavily supported by immigrant workers. Many rural sectors cannot operate without immigrant labour.

National could not support policies that would actively hurt the economy.

Effort needs to go into explaining this, relentlessly.