"What is the average number of offspring for a ball python?"
I assume you are talking about captive bred females here. A large portion of the cb breeding population is young so the average for those that produce each year might be around 6 +/-2. But remember that not every adult female produces for every breeder every year. Rates of production might be as low as 50% in some cases with a few good/lucky breeders having higher rates.
"Do the parents care for their young after birth?"
Almost everyone takes the eggs away so we wouldn't know but probably not. I did try maternal incubation once and the female seemed very interested and attentive as I removed each baby after it came out of the egg but I don't know if you could really call it care. If they do even stay together for a while in the wild it probably isn't very long.
"How long is the gestation period?"
The breeding process is really a year around cycle including preparation but generally breeding occurs about 6 months before hatching but varies.
"Anyone know an estimate of the wild population, and or if they're endangered?"
6.4 - 18 million in 1997. See
http://europa.eu.int/comm/environment/cites/studies/study_royal_python_ghana.pdf
"Any misinformation about ball pythons that should be cleared up?"
That "heterozygous" always means normal looking.
"How many different types or morphs are there?"
There are plenty of less well-known morphs and probably even some well known ones I missed but here is a list of individual mutations (not combinations) I recently compiled:
Albino
Axanthic (Jolliff)
Axanthic (TSK)
Axanthic (VPI)
Banana
Butter
Calico (aka Sugar)
Caramel (aka Xanthic)
Cinnamon
Clown
Coral Glow
Desert Ghost
Fire
Granite
Hypomelanistic (aka Ghost)
Lavender
Lesser
Mojave
Normal
Pastel
Phantom
Piebald
Pinstripe
Red Axanthic
Vin Russo High Yellow Lemon
Sable
Spider
Spot Nose
Stripe
Woma/Pearl
YB/Ivory