ok i know pinky planting isnt very good but when finger picking does like the same rule apply if your using your thumb and index finger to pick?
It's all about technique and the style of guitar that you play. If you were classically trained, a fixed pinky is definitely a no no. Classically trained guitar players are trained to use their thumb, 1st, 2nd, and 3rd fingers. This was the way I was taught, and used this technique for all sorts of styles of play for years. The only draw back for me was finding a way to switch between finger picking for comping, and then a pick for a soloing within the same tune.
When I got into jazz guitar playing, my first teacher got me into hybrid picking. Holding the pick as you would normally do with your thumb and 1st finger, and picking with your 2nd, 3rd, and pinky. It took a while to get used to, but it's been an invaluable technique. In fact, I can switch between the two techniques quite comfortably now.
Going beyond this, Lenny Breau used to use a thumb pick , thus freeing up all four fingers to do other stuff. Typically he would use his thumb for the bass lines, 1st and 2nd finger for two note chords (comping), and his 3rd and pinky to play the melody lines.....all at the same time on a seven string guitar. I actually tried this, but I hated the feel of a thumb pick.
So in my opinion, aside from classical guitar, there are no hard and fast rules. Just limits if your're going to fix your pinky, or just finger pick using your thumb and 1st finger.
Lawrie