Cooking duck and keeping warm?

[T800]

I'm gonna have my first go at making dinner for my girlfriend at the weekend and plan on making duck.
I had a practice go this last weekend making honey roast duck breast. I found to cook it all the way through I had to cook it on it's skin for a long time (felt like I was burning it). The thin breast cooked well but the thick one was still raw in the middle.

What I'd like to know is:
1. If I'm cooking a thick breast how do I cook it all the way through?
2. If I struggle to cook it all the way through could I finish it off in the oven?
3. When they have been cooked can I keep them warm in the top oven for 10 minutes or so without ruining them? (how hot?)
4. The skin was very salty (I used rock salt) should I lay off the salt a bit or use finely ground table salt?

Thanks for any help.

[NOCHEF&JUSTLOVESFOOD.YUM]

I have found that salting the duck breast draws out the moisture and hardens the breast.

I think your heat is too high. Use medium high heat so you cook the fat and not the breast.

If you cook them below your desired service temp you can keep them in a 250F for 10 minutes, yes.

Come on back with other questions.