Allergic, I breed/show Golden Retrievers and would be interested to know who this breeder is and can also point you in the direction of a reputable breeder in your area if you like? (not sure where you are?) I should point out I do not have any litters planned myself, nor have I had one for almost 5 years.
I do wonder if the breeder, by saying the puppies are 'away from Mum' means that they have very limited access to her. This is very old fashioned, but some breeders still do it. I allow my bitches unlimited access to puppies, but after around 4 weeks they do spend less and less time with them and become easily irrittated by them. As a breastfeeding Mum, I can see how 10 large puppies all trying to get at your teats would be annoying to say the least!
In some cases, it is fine for puppies to leave for their new homes at 7 weeks. I have let puppies go at 7 1/2 weeks and like them to be gone by 8 1/2 weeks. I am always happy to keep one or two puppies longer by prior arrangement though, I am in no rush to 'get rid' of them. However, at around 8-9 weeks, puppies enter a 'fear stage' and so it's often easier for them to adjust if they move before that. Also, most socialisation needs to be done before 12-14 weeks of age. Prior to this age they are likely to accept new things and other dogs freely and after they are 'hard wired' to be more cautious of new things. You can carry your puppy and only mix it with vaccinated dogs if you want to be cautious, but I (and after discussion with my vet) do walk puppies in low risk areas after 8 weeks ish, it's good for recall training!
I think it's important that puppies don't leave too early, as this can equally lead to problems. Puppies that leave too soon tend to be a lot more mouthy than other puppies IME and I think the experience of the owner comes into it as well. A week can make a uge difference in the life of a puppy.
Breeders are not likely to be able to socialise a whole litter well enough, so it is not a good idea for them to keep the puppies until 12 weeks, although for some small toy breeds this is important.
As for vaccinations. I personally don't vaccinate puppies I breed. This has nothing to do with costs, but the fact that I prefer first vaccinations to be given at 9 weeks and second at 12. Also, as different vets use different vaccines, then sometimes if they have had their first vac they are told they need to start the course again at the new owners practice.
I'm sure I have seen Minimuu post that she likes ot get her pups at 6-7 weeks, but I could be wrong.