Don't worry. I will not lie and tell you that cats are perfectly safe and docile animals who would never dream of hurting your baby, because the fact is that cats do have claws and will use them when they feel threatened or are miss treated by a baby pulling their tail, trying to hug them, poking them etc. But generally, most cats will swipe with one paw and run away to a safe distance (especially so since the baby will start wailing and cats don't like too much sound). If you have disinfectant at hand and some band aids scratching really isn't something to be overly concerned about since it is very, very, very rare that a wound gets seriously infected. Yes, of course you do not want your little one hurt. On the other hand...isn't it a good thing that the little one learns that when you treat a cat badly the cat will hurt you?
To make the claws less likely to pierce your little ones skin (and save your furniture in the process) you can always try soft paws if your economy allows. They are not all that expensive, but still a cost to factor with if you use them long term since they do need to be re-applied every now and again as they fall off with wear and tear. Soft paws are little silicone caps that you can apply to your cats claws (most people just do front paws) to make them softer and rubber like.
As for the rest...do these people warning you actually know of a real case where a baby has been suffocated by a cat? I don't know of a single one. I hope you don't either. And yet, there are lots of people who have newborns and cats. So even if there might be a possibility, the likely hood is extremely low if we look at statistics.
If you are truly worried, invest in a good baby monitor and just close the door so the cat cannot get into the nursery/bedroom unless you are also there to supervise the interaction.
All in all, I really can't see any reason to worry. Generally speaking, at least older cats pay very little attention to babies since they simply just aren't interesting. They cannot feed them, nor pet them, then what use are they to them?
Don't worry. Just use common sense and I am sure you will be fine.