HAL is one of our favorite lines. You have to remember that any ship and any line will have a few disgruntled passengers and they are very vocal. I remember one poster who criticized the whole dining room experience because the ketchup was in a bottle and not in a silver bowl.
I think you will have a wonderful cruise on HAL and find the dining room to be excellent. The dining stewards are Indonesian, and on rare occasions there will be a slight language problem or a bit of a lack of training. If you feel the service or food is ever lacking, just a word to the Headwaiter will always result in huge efforts to correct it.
Seasickness is a very personal thing. My DW gets seasick frequently, I never do. However, the Alaska cruises in the Inside Passage have a reputation for normally being pretty smooth and seasickness is much less common on them.