I wasn't aware that AIRBNB host in other states can add this tax. I have read posts and it looks like AIRBNB collects some taxes (vancouver and FL a 6.5% tax- although I am not familiar with the tax in those jurisdicitons). I have submitted feedback to get clarification on NH tax and asked to allow hosts to add this fee (or collect it for them).
You mention a new law for 2017 to remit 9% tax, however, I can assure you that if the NH Dept of Rev finds your listing, they will also require you pay all prior year rental tax, which if you didn't pay, comes with a 10% failure to pay and 5% failure to file penatly. To file, a renter is supposed to use form DP-14 or file elecronicly by the 15th of each month. In order to file, your supposed to aplly for a license, 30 days prior to renting (form CD-3).
I rent on other sites and they allow the 9% fee, so it would be helpful if AIRBNB would add this. I think the state Dept or Rev is starting to search sites like airbnb and sending notices to hosts of the tax and license requirement.