You're right, honeybunny, that the baby can be part of bf production....sometimes, if bf gets off to a difficult start, mothers have a hard time later on in keeping up to speed with the baby's needs. There are some physiological reasons for this - it appears hormonal receptors need to be set up with frequent, effective feeding at the beginning to maximise bf success later. That's not to say that a poor start leads to problems later on, as this is not by any means inevitable, but it can be a factor. A baby who feeds ineffectively for whatever reason can reduce the chances of happy bf.
Not sure why GF was brought up as the main cause of calls to the bf line. I won't blow my cover, but this is abso-bloomin'-lutely not true and I am in a position to know, believe me...though it may be true of an indvidual counsellor's current experience. GF is sometimes mentioned, in my experience, and scheduling/frequency of feeds is often a source of grief to mothers, and they can often be helped to enjoy bf and have a better experience if they stop trying too hard to get the baby to feed according to GF or GF-type routines.
Waiting for your breasts to fill up rings alarm bells with me, as this isn't a way to make more milk. I hope I'm not repeating something you have already heard and found lacking, but if a baby is feeding effectively he will remove milk effectively, and milk is then replaced very quickly...the process even begins when he is still sucking. Your breasts may feel fuller after a longer gap, but this is not the result of a large amount of extra milk (a bit like the beach ball which only needs a small amount of air to make the difference between a comfortably pressable beach ball and a hard one). Nevertheless, these over-full breasts then send a hormonal message back to the pituitary saying 'stop making milk!'...over time, this reduces the milk made, especially as the baby is being made to wait between breastfeeds, so the removal of milk takes place less often....leading to less milk.
This time, it will help if you can work with the physiology of bf, and feed your baby often and make sure he is latched effectively so he can make a good job of removing the milk and getting the creamier milk that satisfies him and piles the weight on.
Hope this helps a bit...and sorry if the NCT class was not helpful to you.