Does having wisdom teeth pulled allow crowded teeth to straighten?

No: The most common cause of crowding is due to premature lost of posterior baby teeth. See an orthodontist for treatment.

Slightly: Yes it makes it easier to move teeth but in some cases it needs the intervention of a dentist or orthodontist to assist you reach that goal.

Depends: Depends on the postioning of the wisdom teeth in relation to your other teeth. Having wisdom teeth extracted can free up some space if the teeth are butting up against your molars, but it will not be enough to straigten out already crooked teeth. A full workup with your dentist/orthodontist will give you a much better answer.

Nope: Removing 3rd molars will simply not allow the rest of the permanent teeth to "spontaneously" move backwards in the mouth to resolve crowding.

Sorry, no: Teeth want to move forward, not back. Having wisdom teeth removed will not uncrowd your front teeth. You'll need the help of an orthodontic specialist to do that. Why not call your dentist's favorite orthodontist for an examination and a discussion of treatment options.