When Cersei says the Lannisters will beat your army of Dothraki, Unsullied, and the Second Sons:
Do you have the dragons should be accepted
Yes, this was a contributor sentence, and they didn't list all possible translations. I've now fixed it.
Would there be a difference from "Have you dragons?" to "Do you have dragons?" when translating to High Valyrian, As both are equivalents in English?
No, but the latter isn’t really used in English anymore, so I don’t take the time to program answers like that.
Why is "own" not accepted?
That's now how emagon is defined.