2. You can go in with a pen in the middle, it doesn't matter.
3. Start from the O-shape of D and connect the upper part, and write diagonally to the right, so as to write smoothly.
You can look like a balloon like writing 9. It looks better with a small hook on the tail.
It's just personal advice. What matters is the whole. Don't care too much about individuals. You can't write well if you care too much. Make yourself comfortable.