Samjam, I do feel quite sorry for you(!) - because you have been thrown into the middle of learning an awful lot, very quickly, and having to pick your own way through probably all the hot potato issues in DogDom - all at once - which is a lot to navigate - all whilst raising your first litter of puppies.



Given your head is probably full of puppies at the moment, and that is enough to fill anyone's head, without also trying to decide what they think about all these controversial issues, it's understandable if you're confused. It's not that you are irresponsible.
It is very normal for mum to have diahorrea - she has probably eaten lots of placentas (which cause runny poo), plus presumably you are feeding her a lot/she is eating a lot more (than the nothing she was eating before!) and so all that is going to be going through her body as well. She may also discharge some dark clotty blood stuff when she urinates for many weeks after whelping - which is also very normal. I guess this could look like poop if you don't inspect it closely! Don't give her anything with milk in it - including puppy formula milk, cows' milk, cream etc - as many dogs can't digest lactose and that can cause diahoorea.
With the vaccine situation, IF you are going to be Ms Totally Conventional Following Vet Advice: You would vaccinate at 8wks, and then again at 12wks, with whatever the vet gives - which will include a lepto jab, either lepto 2 or 4. That will mean that you give the pups the first jab and then probably their new owners will do the 2nd jab. If you want to do anything other than that, you are going to need to think for yourself, pick through the information coming from different sources and make a decision for you and your puppies. That is not a dodgy thing to do, it is what good breeders and knowledgeable dog folk do all the time. I would really encourage you to take that approach to everything. NB: If you do give only the 1st jab, you will need to make sure the owners' new vets have the same brand of vaccine as your vet does - or their vet will want to restart the vaccines from scratch to make sure that both vaccines are the same brand(!). If all your puppies are going locally, I would recommend their new owners go back to your vet for the 2nd vaccination - just to be sure the same brand is used and available and to avoid that situation.
My take is: If you are keeping the pups past 8 weeks, you need to socialise them to things away from the house - that's a given. You can be careful about where you put them down on the ground, but I think that if you never put them down anywhere, they will lose out in terms of socialisation. I think socialisation is more important than anything relating to vaccines - because far more dogs are PTS for behavioural problems due to inadequate socialisation, than the small number that die from a vaccine reaction or from catching something they could have been vaccinated against. So I always prioritise behavioural health, whenever making a decision about vaccination. If you are going to be reluctant to take the pups out anywhere at all or put them on the ground without any vaccinations, then I think having the first jab at 8wks would be best. (I would advise NOT having the lepto 2 or 4 jab - you will need to insist on that, with your vet!) If you believe you can carry the pups about, expose them to things in your arms, and put them down in safe areas where other dogs won't have toileted, then delaying vaccinations until they go to their new homes and letting their new owners do all the jabs, would be best. You have 8 weeks to think about it all though!
I agree that asking for a reasonable price for them, is best - and will also reflect the care you are now giving them. Which is much more than many people would.
With the wormer, you really don't need to go to the vet to get wormer for your puppies - you can buy it online without a prescription and it comes with instructions on when to dose and how much to give etc. Look at Panacur 10% paste in the syringe - that is what many of us use. You can buy it online from any pet pharmacy.
With spaying mum, pyometra really is mainly a risk for older bitches - from the age of 6 years+ the risk of pyo increases. Interestingly, having a litter of puppies reduces the risk of pyo in many breeds. And the majority of pyo cases, whilst an emergency, are successfully treated. So, your young bitch which has already had a litter, is not at a great risk for pyo. And meanwhile, there ARE risks for spaying - if you read the links I posted in the other thread that got locked, you will see those. Unfortunately there is no choice which eliminates all risks of everything - it is about choosing which risks you want to take, not finding a perfect answer.
Hope that helps!