There is nothing about kosher sunflower seeds that is explicitly haram. As long as the sunflower seeds were not dipped in alcohol of some type (which is rare), they should be permissible.
For Ashkenazim: no, because they have a custom of abstaining from legumes, peas, seeds, rice (etc.) on Passover. For Sephardim: yes, if the label has a certification of being kosher for Passover.
Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds. Sunflower seeds.
It would have to be certified kosher for Passover.
The label has to say "Kosher for Passover"
Yes, only if they are specifically certified kosher for passover. You can find kosher for Passover olives at any Jewish supermarket
It can be, it would require a valid Passover hechsher.
Yes, it can be since it is made from wine, which can be Kosher for passover if created under appropriate supervision. The bottle would require a kosher for Passover hechsher.
If you were able to find corn vinegar that is certified kosher for Passover, it would be kitniyot which means that the majority of Ashkenazi Jews would not use it.
There are kosher food companies that are now making gluten-free products Kosher for Passover and all-year-round. However, something being gluten-free has no bearing on whether or not it is Kosher or Kosher for Passover.
Arugula is an edible leaf and is kosher year round including Passover.
Yes, they must be certified kosher for Passover though.