"Eddie" AFB carb issues..

When you close the chokeblade all the way,during cranking, the pistons pull gas from every stinking hole under the blade they can. Count 'em, there are a lot of holes.As soon as it starts, the choke pull-off cracks that choke blade open a tad to prevent flooding.
With a manual choke, You have to be prepared to open it a tad right after it fires up.

As to that accelerator pump falling off, I doubt it. More likely are; A) it was incorrectly seated in the first place, or B) it got stuck either on the bottom or to the sides. This would most likely be from water freezing it to the sides. But since you had problems right from the get-go, Ima thinking A, and C) most likely it absorbed something in the fuel and swoll up, or D) the S link was on backwards, or E) some combination of these.
I was pissed. its a brand new Edelbrock 1470, DONT buy this thing. the four tabs holding the gasket in place are insufficient. my gasket loosened up a little slipped right off during acceleration.I was pissed.
Those four tabs are more than adequate. That same pump system has been on probably millions of carbs.

Yeah, my grammar ain't the best some times. And neither is my punctuation.And sometimes I mess it up on purpose to throw a lil spice into a post.Frinstnce;Rusty thinks my paragraphing sucks.