#1
I use a pick to play, but recently i started playing with my fingers. I can find articles about fingerpickings and what not, but i can't find anything on how to strum chords without a pick, are you susposed to use your thumb, maybe a couple fingers together, etc...
#2
Use whatever works for you. I tend to use my index finger's nail for downstrokes and my thumb nail for upstrokes.
#3
it depends on the chord. you usually pluck the root note with your thumb and then the bottom 3 strings with your index, middle, and ring fingers
#4
i'm not talking about playing notes indiviudally, im talking about playing the whole chord at once