I will look into the advanced editor stripping the classes.
As for stopping the multi-sort, I'm not sure. The sorttable.js is an open-source plugin that we have included for convenience. I will need to read through the code again to refresh my memory what it can and can't do. There might be a single-sort class or you might need to do something like double-click to remove the sort from a column. If there's no way, we would have to make a custom solution.