Some noob questions

Hey all. I've been brewing for about 9 months now, and with fall rolling around, thought it would be the perfect time to experiment with a cider. I've tried my best to read up on it, but haven't found a whole lot of good information. That is I still have a few unanswered questions that are pretty basic. Any help would be greatly appreciated.

First, during primary fermentation, do you need to leave head space like you do in regular beers? I wasn't sure if ciders did the krausen thing or not.

My second question has to do with cold crashing. I've read a little bit about it. My understanding is that you stick the cider someplace cold for a while to get the yeast to go dormant. So that's what it is, as far as I can tell. However, I don't exactly understand why it's done. Do you only cold crash if you're racking to a secondary, or do you do it every time? How does it affect the flavor, aroma, clarity, etc.?

Lastly, what should my FG be on a cider?

You don't have to worry about head space, no krausen only bubbles. My understanding of cold crashing is to help the yeast settle or fall out "clear up". The yeast will not go dormant. I am on my first batch of cider. OG was 1.07 after adding brown sugar. It has been fermenting for two weeks @ 68 and has a gravity of 1.01. I'd like to see it drop to 1, but if it's done the it's done. Very dry and not sweet at all.