
Agria/The Kennel Club has policies that covers breeding related issues.
As for your vet's offer, I bet you almost anything that the insurance will be with PetPlan, which you can get yourself anyway and earn yourself some points with their breeder scheme. My last litter ended up giving me £30 worth of vouchers (10 policies activated and 2 new owners took out a year's policy). Unless you are keeping all the pups until 12 weeks (which would really only be for the very tiniest breeds), there would be little point in paying for all the vaccinations. My large pups go unvaccinated just before 8 weeks and the new owners get both vaccinations done -to ensure they can use the same vaccine for first and second vacc (I do not do Lepto 4, or should I say my vet doesn't). My toy pups go fully vaccinated at 10-12 weeks.
Microchipping I do myself thankfully. Worming needs to be done regularly from 2-3 weeks of age so I'd check if your vet really does cover this. Finally I'd never flea treat any animal, especially not a puppy, that hasn't got fleas.
A few things to think about.