"I have a '69 AVS, 4618S, and am wondering about a few things. This plug is supposed to cover an off idle adjustment screw, according to the FSM. Should I gain access to it for cleaning and adjustment?"

What is the build date of your carb/car?
I suspect it is quite an early '69 440 Auto, non air car.

The car was built on September 4, 1968. I found a J8 carb, so September '68 build on the carb was the best I could do.

I wouldn't remove the plug.

I'm sure I'll leave that one alone.

"This is where the idle limiter screws, as the FSM calls them, are located. They are covered by a plug and staked in. Should I gain access to them for the rebuild also?

Not unless you have to, test run the carb first & if it can be adjusted OK with the one screw, leave the plugs well alone.

The motor is stock except for the Edelbrock carb that I'm replacing with this, so I guess I'll leave the plugs and idle limiters alone since I'll still have some adjustment with the one on top.