You do not want to change the full-screen source, because you want to keep abreast of the official branch.
Then the only way is to hide the corresponding lines (hours) after full calendar initialization using javascript:
for(var i=0; i<gapshours.length; i++)
{
var gapclass = '.' + gapsclasses[i];
$(gapclass).hide()
}
for(var i=0; i<sethourhours.length; i++)
{
var hourclass = '.' + sethourclasses[i] + ' th'
$(hourclass).text(sethourhours[i]);
}
After that, you should remember about the periods of clipping and moving events only for viewing purposes.