Feels like it's really a castle from fairy tales that hidden somewhere in forest. I think that it's a great idea to leave some detail of bark not carved, I am enjoying all the details! Amazing job!
Yeah, people sometimes ask me if they could put those in their gardens... It would look pretty nice but I think the bark wouldn't survive outside for too long.
Many people put big or small wooden sculptures in their gardens and, I think, there is something special for these purposes: protective stain and lacquer or anything else. And it really would look nice in a garden!
There are some products but they need to be re-done once a while. I have lots of driftwood woodspirits around the house, they get beaten a lot, especially during winter, but they are wood spirits - they must endure :)