No. The "lead" pencils do not have any lead in it, therefore no risk of poisoning. There's a risk of foreign body in ears or nose, so try to keep toddlers away from them anyway...
Absolutely NOT. Lead from a pencil is nothing but carbon (like charcoal). This is different from lead, the chemical element lead, that is used in many chemical preparatins such as paint, batteries, soldiering and the like. The chemical lead is very dangerous to your health whereas the carbon in the lead pencil is more of a tattooing and inert. Cerainly the wound from the stab or stick should be treated.
Unlikely. If she only put it in her mouth briefly and did not eat the pencil lead and has not done this before on several occasions it is unlikely that she will have lead poisoning from this one time. But if you are concerned and unsure about how much past exposure she may have had she can have a blood test for lead level by her doctor.
Yes. Pencil lead is actually a non toxic material called graphite. Unpainted pencils only a problem if baby bites off chunks and chokes on them. I don't believe that the paint on pencils is a problem if they are made in the us. I have reservations for any painted material coming out of china as they may have toxic material in the paint.