@SBrown, you'll have a blast!!!
Otaru is a charming seaport, definitely worth walking around shopping district and fish market. There is a prominently located sushi bar (Tori ton?) in town, conveyer belt style, very fresh and good value. And uni fan? Hokkaido uni is the holy grail.
https://mobile.nytimes.com/2013/07/21/travel/in-japan-searching-for-prized-sea-urchins.html
I had a blast skiing Tengu one afternoon/evening with my nephew and niece. We went a fantastic onsen nearby afterwards which also serves amazingly authentic and delicious South Indian curry and naan on site will have to look up the name.
LOVE Furano and Tomamu!!! Missed Kamui, it seems to have such mixed review.
Regarding tipping, not in Japanese establishments. However, western guests of local Western tour guide companies do routinely tip.
@Mattadvproject, I remember many westerners on Furano gondola wearing airbag packs. Do have any recommendation for your clients?
Perhaps I can overlap a few days with you guys on my trip as I'm due to visit family in Sapporo next Jan/Feb.