In my private lesson with Fretmentor, we studied fingerstyle techniques. It was timely, (and a good break from scale and chord structure). I was reading a Frets article from a 1985 copy from the Fretmentor collection, and i found a very comprehensive article on fingerstyle blues, complete with tabs. Now that's just cool.
I play finger style at least 50% of the time. Maybe more. On some songs it's a must (Blackbird for instance). When I'm just making up stuff it's usually without a pick in hand. I tend to have my own style as I've had trouble getting three fingers to work together at one time in the traditional fashion. Right now I'm more of a thumb & two finger guy. Who knows...maybe in time if I try long enough I can get'em all to work together. Maybe I'm just too lazy. I sometimes play our bluegrass tunes without the pick but somehow feel like I'm just asking for trouble.
I don't think the Fretmentor cares whether you use fingers or pick, as long as you get a good "boom/chuck" in the rhythm. Though he is a bluegrass purist,he may prefer the pick.
Actually, your thumb and 2 finger routine is preferred by the fretmentor. He says it's simpler, and you can anchor the un-used fingers to the instrument to keep your hand in position. I don't play any fingerstyle, it's something i need to work on. (when i'm done with our songs of the week of course, and our assigned song for the end of the quarter)
Fingerstyle playing is great, I play that way a lot and actually prefer it. Most people seem to play three fingers (this is FM's preferred method too) and some workshops I've taken teach the 3 finger method...thumb and #2 and #3. There are some very good fingerstyle players (and teachers)who use four fingers, like the classical guitarists. This can be an interesting variation although FM frowns on this!!! I use fingerpicks for 3 finger method, but can't quite pull it off with fingerpicks if I play a piece that uses four. Have to go with just plain fingers......
You can train or be trained for fingerstyle, but for me at least, the difficult part is getting a good tone out of the guitar, with our without fingerpicks. I find that quite challenging.