is it normal for a 9 wk old staffie pup to have creases on its forehead? the breeder said his head will grow into his skin

Sjould pups be very chunky or not this one was not chunky at all but his brother was, the breeder commented it was greedy and the other one wasnt

Should the dog have a pedigree from KC this was a home made one

Can't answer your Staffie specific questions, hopefully someone will be along soon that can, but it is entirely normal for the breeder to handwrite the pedigree however the registration document is something else and is printed by the Kennel Club.  If the breeder does not yet have this in their possession to show you you should get it in writing that the Kennel Club Registration Document will be sent on as soon as it is received.  No other registration organisation is worth bothering with in my opinion.

the creases on the pups head are normal, staffie pups have this wrinkled expression but it does dissappear as they get older.

As for the pup being chunky, staffie pups usually are quite chunky, solid little pups, and if you feel that the pup you saw is quite thin in comparison to its littermates it might not be a good idea to buy the pup, especially if its noticeably thinner or has ribs showing. Good breeders will make sure there are no runts in the litter by supplementing the feeding of any pups which are not as robust as their littermates, and if theres anything wrong with the puppy they should not be selling it to you, or you should be made aware of its condition at the time of sale.

Isabel is right about the KC papers, you must get it in writing that the papers will be sent on, allthough its best if you can get them at the time of sale, the Kc are pretty good with paperwork for pups and if the breeder sends off for them early enough they should be ready at the time of pups being sold.

Good luck :-)

Just to add, don't be too alarmed if the papers are not yet available there are several perfectly reasonable causes for this for instance a rejection of the name due to duplication with another dog or applying for an affix at the same time as registering the litter but the breeder should be able to tell you if this is the case and you will be able to confirm with the KC that application for registration has been made.