It’s always fun to see which search terms people used to come to my blog.
what is safflower used for
I’m not sure, I only know you can make oil out of it which presumably can be used for everything other oil is used for. I have a post on whether safflower seed oil can be used on pessach (spoiler: yes).
isswiss muesli hametz
Muesli usually contains some of the five grains that are chametz: Wheat, barley, rye, spelt, oats. So I say, yes, it’s probably chametz – unless it’s kosher-le-pessach muesli 😉
If we are talking about the same thing, kasha is some porridge-like stuff. Whether it is kitniyot depends on what it is made of, usually that would be buckwheat, sometimes millet or other grains like wheat. Wheat, barley, spelt, rye, and oats are chametz. Buckwheat and millet are kitniot.
string beans on pessach 2013
The situation does not change (or at least should not change) for a specific year, so the answer from 2013 should still be good for today. Unfortunately the situation seems to be tricky, divided between those that say that there is no problem with string beens as they are vegetables, and those that say they are beans and thus kitniyot (links and discussion in my post about beans).
is sodium bicarbonate chometz?
No it is not! (this is relevant because baking powder is made out of sodium bicarbonate)
is ginger kitniyot
No, it’s a root, not a seed, why should it be? The question is valid for other spices that are seeds, though.
“pumpkin flour” passover
Ok, I have no idea what you mean, but most people say pumpkin seeds are not kitniot and so if you make flour out of it that should be fine.