Hello @Jay220 ,
A special offer overrides al normal pricing and discounts. That's why it is a "special offer"! It has to be accepted by the guests within a limited time, otherwise it expires (which will not affect your responsrate)
For long term stay (28 nights and more) automatically the long tem stay cancellation policy applies. Guest will be charged indeed 1 month at the time. But if you are a new host, first payment to you CAN be hold to up 30 days.
I suggest you read this articles fro more details:
https://www.airbnb.com/help/article/1361/how-do-changes-and-cancellations-work-for-long-term-reserva...
https://www.airbnb.com/help/article/285/how-are-long-term-reservation-payouts-processed
best regards, Emiel