7-day Northern Kyushu

Hi,
We're leaving for Japan on the second week of January. Our arrival and departure is through Fukuoka Airport and we're looking at the following itinerary:

Arrival: from Fukuoka Airport to Nagasaki
Day 1: Nagasaki - Saga - Nagasaki
Day 2: Nagasaki - Fukuoka
Day 3: Fukuoka - Kita Kyushu - Fukuoka
Day 4: Fukuoka - Yufuin
Day 5: Yufuin - Kurokawa Onsen
Day 6: Kurokawa Onsen - Mt. Aso - Kumamoto - Fukuoka
Day 7: Fukuoka (Departure)

We plan to use 5-day North Kyushu Pass from arrival to Day 4 (Yufuin). Then from Day 5 to departure, use 3-day Sun Q Pass. Is this manageable and economical? We already made accommodation reservations for the Kurokawa Onsen leg of the trip, all other days are tentative.

Many thanks. ^_^