Seeking Advice on travelling around Okinawa via Public Buses

Hi all,

I will be headed to Okinawa in August and have the current hotels booked:

9 – 11 Aug: Nago
11 – 13 Aug: Okinawa City
13 – 16 Aug: Naha

However, as I am not renting a car, I would like to ask the following:
– If I board the Yanbaru Express Bus (YKB888) from Kencho Kitaguchi (Okinawa Prefectual Office) 県庁北口, would I be able to retrieve the luggage easily when I disembark in Nago?
– Is it advisable to take public buses (e.g. Public Bus 111 from Nago to Okinawa City) with a medium sized-luggage (24 inch)?
– If all else fails, I am thinking of Ta-Q-Bin to send my luggage from Nago to Naha on the return trip. Is this available at all 7-11s around Okinawa?

Thanks in advance and really appreciate the help!