Crooked teeth. Sometimes. If the adult tooth grows out and the baby tooth is still present then the adult tooth can grow in the wrong spot. If you pull or lose a baby tooth too early then this too can cause crowding because the teeth collapse together trapping the adult tooth. Best to consult with an orthodontist early (by age of 7) to monitor the eruption of teeth. Go to www.Braces.Org for more info.
Probably not. Crowding and crooked teeth resulting from removal of baby teeth is usually premature removal and not maintaining the space left by the baby tooth. If the baby teeth are over retained and the permanent teeth come in crooked, it is more likely due to inadequate arch length to acommodate the permanent ones.
Could be. Over-retained baby teeth can cause alteration in timing and position of underlying permanent teeth. Probably, though, this is just one of the many things that have been going on at the same time. Ask your dentist for referral to an orthodontist for an answer specific to your problem-set.
See below. This unlikely to cause crooked teeth.