Given the background description of some cooking related query, summarize the question into a title

[EX Q]: To which temperature could I safely heat my cast-iron pan on the stove, without any contents? I don't want to re-season it afterwards. Afterwards, I'd just let the pan cool off in room temperature. The base is ~0.5 cm thick.
[EX A]: How much could I safely heat a content-less cast-iron pan?

[EX Q]: My icing is 1/4 cup butter to 1 1/2 cups of icing sugar and a couple tablespoons of milk, so I'm thinking that with so much sugar, the answer is "almost indefinitely in the fridge."So, as the title says, how long is it reasonable to keep the remnants of a batch? Although I've made small amounts (like the above recipe) on occasion, I'd like to make a big batch, seal it up, and use it as needed.(I realize that it might not work as well a month or two down the road, I'll experiment with it if I decide it's ok to use.)
[EX A]: How long does butter cream icing keep?

[EX Q]: I got ten pounds of rye flour from the amish store yesterday. They only had a single, two-pound bag sitting on the shelf but, when asked, the man behind the counter said they actually have lots of rye flour but keep it all in the freezer because otherwise Something Bad will happen to it. It's organic and I think it might be wholemeal but I'm not sure.I haven't been baking for terribly long, maybe 8 months or a year, but I've never frozen my rye flour. Is this a legitimate need? Ten pounds of flour takes up more freezer space than I would prefer. Thanks!
[EX A]:
Do I need to freeze my rye flour?