It all depends on how you subjectively "view" the subjects. If you view them as a single item, you can use "is" (singular).
Bread and butter is my favourite food.
If you view them as separate items, you use "are" (plural):
Bread and rice are not expensive.
For your examples I don't think MS Word is intelligent enough to know what you are thinking. And nor am I. I'm guessing you're talking about football, though I'm not sure. And while I suppose that scoring and dribbling are important activities in football, I'm not sure that they go together. So I would probably prefer:
Scoring and dribbling are important.
Same for #2:
Scoring, dribbling, and assisting are important.
Trying to find a sports example that might be considered singular - because you view it as "one" - I come up with:
Warm up and stretching is important.
"We are not wholly bad or good, who live our lives under Milk Wood"
prayer of the Reverend Eli Jenkins in Under Milk Wood by Dylan Thomas