Pastors in the Southern Baptist Church must give up their duties if they become divorced and remarry while their first wife is alive. It is considered adultery. Pastor Jeff could go to some other churches to preach, but not a Southern Baptist church.
When Sheldon and Missy spray Meemaw with the fire extinguisher, it produces a cloud of CO2 gas, but the next shot shows Connie covered in foam, which that type of extinguisher should not produce. EDIT: The CO2 extinguisher left Meemaw covered with frost, not foam.
Pastor Jeff shows Mary the VISA card his wife had and it's the old "full face" design that was used up until 1984. Even by 1989, the time-setting of this episode, those card designs were phased out in favor of cards with the smaller VISA logo and the bank's design on it.