all fingers under is fine if you can.
but it requires more wrist flexibility.
the first 2 fingers makes it easier,
They are not there to hold the bar really.. just to anchor your hands somewhere so you can push the elbows UP.
and yes..
right up in to your throat.
I get my fingers where I want them, then the feet under, then swing one arm under, then the other as I put my head right back so the bar is right up against the part of my throat and clavicle meet.. then bring my head down.
as you stand up and have elbows up, the bar ends up sitting on your front delts rather than the clavicle.
then it's a big breath in, chest/elbows up, back arched, and squat down between the heels.
This shows where I mean by on the throat/clavicle.. ignore that his hands are not on the bar.
and what I mean by 2 fingers..