You can not buy a house, but you do take over a battle tower about a third of the way through the game, and acquire servants and a storage chest.
When you first become a dragon you will be targeted fairly quickly, and hovering in place for more than 3 or 4 seconds without any cover would be a bad idea, but the ballistas fire straight at you, so from a distance even a very slow flight would make it easy to avoid the attacks (flying opponents take a bit longer to get to you, and are not in a big hurry to attack if you are far away). There are areas where you can transform into a dragon and get attacked fairly quickly (not immediately), but that is rarely ever a problem (in human form you can see if there are any flying opponents around, or any ballistas, or other anti-dragon defenses).
You get a brief taste of the dragon form earlier in the game, where there are not many opponents, and can fly around there to get a feel for it.
