Black / dark-skinned.
Drishtadyumna
black
black
Dark
She was dark coloured.
As she was daughter of "Agni Dev". Agni means fire and dev means lord.
droupadi
The original name of the Mahabharata is Mahabharata.
Yes, Mahabharata is a true story.
There are number of heroic things that Arjuna do in Mahabharata. The list is long and beyond the scope. Better you read the Mahabharata. Rather study the Mahabharata.
Ajaamila is personality who comes in Srimadbhagavata, not in Mahabharata
One highly recommended Mahabharata translation is "The Mahabharata: A Modern Rendering" by Ramesh Menon.