I’m only about 5 batches of cider worth of an expert, but my experience is as follow:
You probably want to treat non-pasteurized cider with Campden tablets before pitching. This will prevent the wild yeast that are present in the juice now from going crazy or giving you off tastes.
My first batch with fresh pressed apple juice I did not treat it at all, and it came out great. But all batches since I’ve treated rather than risk the batch.
The only way to keep it from getting too dry is to kill the yeast at the gravity you want. In my opinion, it’s easier to let it ferment out completely, stun/kill the yeast with a combo of Campden and K-Sulfite, and then backsweeten it to taste with whatever you like. It’s seems most common to use apple juice concentrate or lactose sugar. I rendered a batch undrinkable by adding to much concentrate (it was WAY too sweet to drink), so sometimes less is more.
It’s been said on the board before, and seems to be true, that you can use virtually any yeast you have on hand. My batch I have going now is with SafeAle-05, simple dry yeast.