OSAKA airport to Osaka city & Fukuoka

I have purchased a 7 day JR pass.

Itinerary
Day 1 - Osaka Kansai airport. Check in hotel
Day 2 - Osaka - Tokyo and back
Day 3 - Osaka - Fukuoka daily return
Day 4 - Osaka - Fukuoka daily return
Day 5 - Osaka - Hokkaido daily return
Day 6 - Osaka - open
Day 7 - Osaka- Kansai airport

My question
1) I will lannd in Osaka Kansai airport (7am) and plan to go Osaka city by trains covered by JRpass.
2) Instead of staying in Fukuoka in Day 3-4, I plan to put up in Osaka hotel for my entire visit. Is this possible?
3) Do I need to purchase any other train passes?
4) Please suggest any possible routes with interesting places covered by JRpass.
5) My travel plan is flexi except I need to be in Fukuoka (8am-5pm) in day 3 & day 4.

Thank you.