1) I'm not sure but I believe the the original was Blind Alfred Reed; if it wasn't, it should have been.

2) Yes, it is "bobed" and I have never been sure whether that was from scansion rquirements or inability to spell.

3) Modern versions sing some of the middle verses as

They wear their hair in the latest style, S P I K E D
And up their nose they snort their C O C A I N E
And then they have the brass. . .

4) The Georgia Yellow Hammers sing a much simpler chorus:

I'm S A V E D, I am, I'm S A V E D I am,
I know I am, I'm sure I am, I'm S A V E D

5) Another later verse goes

I know some folks who S M O K E and also chew
They say they're C H R I S T I A N S too,
But when to J U D G M E N T they go
The J U D G E will say "smokehouse down below"

Pete Peterson, from a borrowed computer in Atlanta