Common. It does happen.
They can. And if they have no space between them there is a 60% chance that the permanent teeth will be crowded. Check with your dentist to make sure there are no underlying problems, but other than being harder to clean, crooked baby teeth are usually not a problem. Have an orthodontic consultation at age 7, when the permanent teeth begin to erupt, to determine best treatment options.
Yup! That's due to genetics moslty but enviornmental things like binky or finger/thumb sucking can cause it as well. If you are concerned see your dentist. They should be seen by age 1.
Crooked teeth. Yes. Unfortunately those little teeth have a mind of their own. If they come in crooked, don't worry too much about it because it is not an indication that the adult teeth will come in crooked. Consult with a pediatric dentist to learn more.