From what I was told, the bells were rung to alert the parishioners that the Eucharist was being consecrated during the Latin Masses. Once the Masses were said in the vernacular, parishioners didn't need that signal anymore, however, tradition is hard to break, and many churches still continue this practice. My church stopped the bells in 2001, but I still hear them in my head, too.
We were also told that the American bishops had fought to keep the kneeling in American churches because Americans hold kneeling as a symbol of veneration. However, I believe the churches in Europe all stand from the Great Amen, and so we now also stand. In my church people also start from the back to the front to receive Communion.
Some of us kneel after the Eucharist has been returned to the tabernacle, and most sit.