not sure what you mean "crushed of the map" you mean X'd on the map? it's a known glitch, happens with legendary fish also. go back to an earlier save (hopefully you've been manually saving before each of these).
Sure was simple, somehow I missed it has to be from behind. Hanging dog ranch is great for this btw. Hide in the brush take out the guy in the tower, then there's a walker to your right wait for him to turn away, etc. Got all 9 right there, only had to run and reset once, too about 20 minutes.
you can hunt all the legendary animals but the 3 in New Austin, I would strongly suggest hunting and getting the Legend of the east Satchel. Also start the legendary fish, you can catch all but 3 of them, the last 3 being in New Austin.
There's the challenges - the gunslinger, bandit, herbalist, etc.
I've been playing the game almost every night since it's release, and i've only made it into chapter 4, because i wanted to unlock that dead eye bonus. You have to unlock the horse fence in chapter 3 for a bandit challenge.
Then there's the treasure hunts,
Then finding all the rock carvings.
then finding all the dinosaur bones (there's a few in New Austin),
then just going out and exploring and seeing all the awesomeness that's in the game.