Yes, they are safe to eat. Just like when an apple slice has been left out turns brown, avocado exposed to air turns brown as well. Try to consume your avocado the same day you cut it.
yes
Yes, the skin is just damaged, not the part you eat itself.
Mold-no
Yes, you can.
In the center of the avocado is a pit. The pit is usually larger than a gumball, and is a dark brown color. Surrounding the pit is the light green flesh of the avocado. The flesh achieves a more pasty quality as the avocado softens and ripens. Finally, covering the light green flesh of the avocado is a rough dark green-ish brown skin. The skin and pit are typically removed when eating the avocado.
Yes. It's just oxidized. But don't eat it if it's moldy. Taste isn't quite as fresh but it won't harm you.
If you are eating a snack you can eat a avocado.
No, you can eat it raw
No.
Yes.
Resplendent quetzal
yes