@29632963 There sure are! The short answers are:
2: Add a second edge loop right next to the original edge to sharpen it up.
3: Add in three edge loops to make a square where the main part of the door is, and delete that square. Then add in five edge loops from the top and pull those up so that the hole matches the shape of the door.
These two courses will answer in much more detail:
https://cgcookie.com/course/introduction-to-hard-surface-modeling
https://cgcookie.com/course/mesh-modeling-bootcamp
Good luck!