Sandman, yes I do sometimes use four fingers as in guitar playing. But with just five strings and using the thumb on the third string from the bottom as well as on the two strings above that, the middle and index finger are enough really. The greater use of the thumb also gives a different sort of sound. This style is used mainly for bluegrass, but I've always been more comfortable picking rather than strumming. And what little instruction I've had on banjo has been at bluegrass weekends.

So I'm still looking for suggestions of recordings I could listen to, and maybe watch, of people using the t3 finger style (thumb, index and middle string) to accompany old-timey songs, ballads, "folk songs" - accompaniament in those genres rather than instrumentals or bluegrass.

Re learning a few styles at once, there are so many picking patterns to practice just in the three-finger style, that doing much more than that at the beginning would be overload!