
Just read your "not rocket science" post, and then this one. Without getting into the sort of discussion which your other post will possibly provoke, I think you need other quesitons before these ones. Way before looking for breeding complications etc. you need to ask questions about the how to interprate the breed standard, get opinions form knowledgeable people about how you bitch fits and does not fit to the required form, hwo to find a stud dog who will compliment her (supposing she is good enough to breed from). Your first port of enquiry should be her breeder, who should be in the best position to give you relevant family breeding history, how the family "throws" when mated to certain lines/types of dog, etc.
With your whelping related questions, the answere ot these are mostly based on experience and knowing your bitches, you interpret signs, and it is very hard to actually pass this info. on verbally or in writing, it comes with time. OF course, every breeder has to have a learning curve, and this is where your bredeer/mentor comes into it. Someone who will literally sit with you thorugh the whelping and give you the benefit of their expertise to teach you and help your bitch. Pugs are notoriously not easy to whelp, can give conflicting signals, and are mostly unwilling to have anything to do with the new born, so you need to learn to clean off and get pups going, too. When breeding all dogs, and especially one like pugs, saving time and money on vets is not on the list of priorities, the bitche's (and pup's) welfare must ocme first, so any sign of distress needs a vets visit.
Just wondered, you have not mentioned showing your pug, is she a family pet? Why do you want to breed from her?