I have browsed the other closed threads on this topic, though can't find a completely satisfactory answer to my problem.
I am aware of the general rule that we use "for" when someone benefits from the action, and use "to" when the object moves in the direction towards something or someone.
However, I'm not sure this really applies in a sentence like:
"It is very important to us"
"It is very important for us".
I'm struggling to find a concrete rule here. To me both sentences are correct. I would say the meaning in the first sentence shows our opinion/subjective feeling, and the second sentence perhaps shows something which is "good for us" (objectively?).
Can anyone help me escape this cloud of uncertainty, so I can resume being a teacher who isn't just guessing the grammar as he goes along!!
I think in a lot of cases, you could use either after important, but I would say She's very important to the team (= she is an important member) and I wouldn't use for there. If something is external, a bit like your subjective/objective, I think I would be more likely to use for.