I got a 2.5 yo border collie/heeler mix last Tuesday (the vet thinks he may have some bull terrier as well). He was in a foster home for the last three months.

-How do I get him to pay attention to me in highly stimulating environments? He does excellent in the house, pretty well in the backyard, and mediocre to poor on and off the leash outside the yard. He is aware of me but generally doesn't pay enough attention for me to get him to follow commands.

-He is not crate trained. Right now my living situation doesn't require him to be crate trained. Will he be confused or upset if I crate train him at some point in the future instead of now?

-Do I need to correct everything immediately eg: if I let him pull on the leash some of the time (most walks I make him stop and come back to me every time he pulls before we go on) is that bad? Am I screwed if I decide in a month I don't want him sleeping on the bed?

-Unless I'm holding the food (and sometimes not even then) he is not food motivated. I am teaching him fetch but he'd rather I chase him around while he has the ball and I don't want to reinforce that behavior. What are some games I can play with him to get him mental and physical exercise?

-Right now his only two bad habits are ignoring me outside the house and chasing small animals. Is it likely that any other bad habits will develop slowly enough for me to recognize and correct them before they become major problems?