Kyushu 15 days

We are bringing along our daughter, who will be 21 months then, to Kyushu from end March to early April 2018. We will appreciate comments if below itinerary is sound.

We still have one day which is empty. Any advise which part of the trip that we should extend to use that one day?

(Sat) Day 1 – Arrive at night. (Overnight in Fukuoka)

(Sun) Day 2 – Uminonakamichi Seaside Park if there is early bloom. Else, explore Fukuoka city e.g. Canal City. (Overnight Fukuoka)

(Mon) Day 3 – Pick up rental car/ Suwa Shrine or Yotuku Inari Shrine/ Mt Insana (overnight Nagasaki)

(Tue) Day 4 – Glover Garden/ Dutch Slope/ Megane Bridge/ Chinatown/ Nagasaki Peace Park and atomic bomb museum (overnight Nagasaki)

(Wed) Day 5 – Unzen/ Shimabara/ Kumamoto (overnight Kumamoto) - with the earthquake, what are recommended places to visit in Kumamoto? Else it will just be a point for stopover

(Thu) Day 6 – Mt Aso. Overnight Mt Aso or Takachiho? - understand that we couldn�ft get close to the crater. Any idea where is a good viewpoint instead?

(Fri) Day 7 – Takachiho Gorge (Overnight Kurokawa onsen)

(Sat) Day 8 - Overnight Kurokawa onsen

(Sun) Day 9 – Mount Tsurumi/ Beppu Hells/ Steam cooking at Jigokumushikobo (Overnight Yufuin or Beppu?)

(Mon) Day 10 – Walk around Yufuin town (Overnight Yufuin or Beppu)? -Would Yufuin or Beppu be a better place to base ourselves?

(Tue) Day 11 -

(Wed) Day 12 – Kurume Taiho ramen/ Tosu Premium outlet/ Fukuoka

(Thu) Day 13 – Uminonakamichi Seaside Park

(Fri) Day 14 -Fukuoka shopping

(Sat) Day 15 – Depart morning flight

Thank you very much!

It would help a bit of you gave more info on your interests, as well as you mentioned getting a car from your Day 3 - are you planning to use it for the rest of your trip, or just for that area?

For your Day 2, there is a lot more than Canal City. Try looking through
http://www.thejapanfaq.com/fukpic.html
Plus if you are hoping to see the cherry blossoms, I'll let you in on one of the best kept secret places in the whole area - if your timing is right, go to see Kayoicho Park in Kasuya, just outside Fukuoka. Extremely few people, and of the best displays you will ever see.
https://youtu.be/pYKNmvevAC4
You could also combine it with a visit to Nanzoin, one of the finest temples in the country, yet also a virtual secret unknown to most, even the well traveled.

For your Day 3, the Yutoku Inari Shrine is a good choice. And if driving, the Arita Porcelain Park is not too far out of the way and will be really surreal for you - like leaving Japan and suddenly stepping into Germany for a while.
Regarding Day 4, the Dutch Slope & Megane Bridge are rather underwhelming. But don't miss the Koshibyo Shrine. Dejima is worth seeing too.
In Kumamoto, the castle is still closed. The other big sight is the Suizenji Garden, and well worth it. There are a few other minor places of interest.
For Day 6, it's up to you where to stay, but Takachiho has Takachiho Shrine with its nightly dance. It may or may not appeal to you. You are right that the Aso crater area is off limits. But if the weather is clear and you are driving, there is the Daikanbo Lookout which has a spectacular view. The Nabegadaki Waterfall (west of Oguni Town, down Rte 387) is very nice also, particularly just after a lot of rain. Another delight in the area is the Kuju Flower Park.
http://www.hanakoen.com
For Days 9/10, both are not far from each other; you could stay at either, but Yufuin is a lot more tranquil or dull, depending on your style. Near Beppu is the Takasakiyama Monkey Park & Aquarium, which might be enjoyable.
http://bit.ly/2pZ9opz
And for Day 11 - there are many possibilities. You could visit Yanagawa with its canal boats, Dazaifu, the Kunisaki Peninsula, Furen Limestone Cave, Usuki stone Buddhas, and lots more.

No need to overnight in Mt Aso unless you wanna explore and visit the caldera towns surrounding Asosan.

There is a Mt Aso museum and viewing point close to the peak.

Website for museum:- http://www.asomuse.jp/

Also Takamori is worth a visit on your way to Takachiho :-http://www.town.takamori.kumamoto.jp/kankomap/kanko/yusui.html

Kumamoto - I'd enjoy the smaller city atmosphere. It's a nice place to chill. There's a really good local crafts museum close by the castle, and also do pop into the contemporary art museum right in the centre of town, just by the covered arcade, even if it's only for 15 minutes to see the Marina Abramovich installation in the library area (shelves for people to sit and lie on, built into the book shelves), the James Turrell installation in the library (look up - it's in the ceiling), and the Yayoi Kusama bubble/mirror installation which is tucked into a tiny space under the stairs from the library level to the next level.

Aso region - don't miss out on the quiet lovely rustic onsen ryokans that are in that region https://kumanago.jp/en/spots/hotspring/search/?onsen_id=1 the place with the mud baths was really lovely to stay in, and a contrast to Yufuin or Beppu (and even Kurokawa - which is quiet, but more developed and slick than Minami Aso), and the food was awesome (they have a lazy river in the dining hall that delivers your breakfast eggs to your table!!)