#1
Do you fingerpluck with all your fingers? I realised that I use my thumb, index and middle fingers to pluck the guitar strings most of the time. Will my technique improve if I use all my fingers to pluck the strings?
#2
It's pretty unheard of to use anything past the ring finger to fingerpick, so I'd recommend just adding the ring and seeing where it takes you. I usually add my ring finger when I'm playing rhythm or chords, and leave it off when soloing.
Fender American Standard Telecaster
Vox Night Train 15W
An ever-morphing BOSS and MXR loaded pedalboard

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-Howlin' Wolf
#3
In classical guitar we learn that the from the thumb, we call it P,I,M,A.(thumb, index,middle,ring fingers respectively). I dont think i can recall ever going beyond the ring finger. The pinky finger could be used but it takes a while to train the muscle to be able to pluck consistently and properly. Good luck!
My rig:
Yamaha CG-110A
Ibanez RGIR20E
Laney Linebacker 5

"My guitar is not a thing, it is an extension of myself, it is who i am" -unknown
#4
One thing i've been doing recently when i'm just noodling the blues is hybrid picking.Just using my pick for the E,A,D strings and using my other 3 fingers for the G,B,E strings.Just introducing them slowly and making it kind of habbit to get those fingers involved a little more,It is becoming more natural to me slowly.Also practicing jazz II,V,I progressions in the same way,Using my pick for the Low E and A while assigning my other fingers to the rest of the strings,Now it's becoming less of a conscious thing and just something i do.Just practice really until it becomes habbit.