I am the "Goose Queen" (boy does that sound weird - lol). My mom & I have been roasting geese for Xmas since I was a young sprout (& I'm 50 now, so that's a lot of geese).
The very very BEST way I've found to roast goose, a method I've been using for several years now, is from Julia Child's book The Way To Cook. While it involves several steps, none of them are beyond anyone's ability & you end up with a juicy, relatively greaseless, very tasty bird.
The recipe itself looks very long, but is easy. If you don't own this cookbook (& believe me it's worth every penny if you can find a copy - even a used one), check your library.
If you still can't find the recipe, I'll wrassle it up (lots of typing - lol!!). In fact, I think I did post the recipe here last Xmas when someone else asked about it. Maybe do a search here on goose?
As far as when to start defrosting the bird - my method is unconventional & unapproved (but I do it anyway - lol!!). Two days ahead of time I take the bird out of the freezer & stick it in the oven (to avoid cat & dog interest) during the day. At night I stick it back in the fridge (it's still cold & solid as a rock at this point). I do the same the next day, & when it goes back into the fridge that 2nd night, it's still icy cold, but not rock hard. It then stays in the fridge & is perfectly thawed by roasting time.
Again - unconventional, & - I know - tons of folks will say dangerous. But what can I say, I've been doing it this way for 30 years & it works for me.