I'm a neonatal nurse within a SCBU and we have nursery nurses that work in our unit too who do a great job.
You'd need an NVQ like you say, but not any experience if you're lucky (though you might lose out if you're going for a job against someone that has more experience, as you might in any field).
The job itself would be pretty much like you say- working with the 'well' babies within a SCBU unit, so the babies who were born prematurely or sick and who are just growing and learning to feed by themselves. You wouldn't be expected to give medication, handle IVs, blood transfusions etc. Some babies may be on monitors so you'd need to have a basic knowledge of baseline observations eg, pulse, temp, normal breathing patterns etc in order to distinguish when something is wrong. Unfortunately quite a few babies, particulary those born very prematurely will have a few tries in the nursery (where you would be based) only to get sicker and have to return to a higher dependency area, so you'd need to know what to look out for.
Good breastfeeding knowledge is invaluable also, you only have to read the bf threads on here to see some of the shocking advice that's bandied about by hcp who are supposed to know what they're doing . Other than that, it's down to personality I'd say. I've worked with a lot of nurses and NNs and some are good, some are bad but the good ones can really turn around a parent's experience of having a sick baby. Likewise, good nursery nurses help make a nurses job a thousand times easier.
Does that help? If you don't already have an NVQ have you thought about just doing paediatric nurse training? It takes three years and is hard work (though I presume the NVQ course is too) but if you're thinking about doing it, now's the time as you can apply for the diploma and get a bursary to train and they're stopping that in a few years so all nurses will need a degree and have to fund themselves .