Prohibiting protesting at funerals deprives no one of a liberty they should have. Should people have the right to stage a march in a church? How about in a public school? Not protesting at funerals is just common sense and decency that shouldn't have had to be made law.
I agree with the first part of what you say- it's not depriving them of a liberty they
should have, but it is depriving them of a liberty that they
do have....and are guaranteed.
Saying "well, yeah, but they are over the top, they are deliberately being provocative, they are trying to provoke civil unrest" is conjecture on our part- it's not up to us to examine the motives of protesters as much as it's up to us to defend their right- hell, ALL our right- to protest.
The second part- protesting in a church or a school- Churches are basically private property, so protesters are trespassing- if I had a church and a bunch of people used their first amendment rights on me I'd call in a bunch of my 2nd amendment friends and evoke my fourth amendment rights to clear my church. My second and fourth amendments trump your first amendment any day.

Schools? If I have a minor child in a public school I have a reasonable expectation you will not allow my minor child to be subjected to school sanctioned political POV displays. Sorry Rip, but we disagree- Schools at the primary level do not have the right to host controversial guests who will engage in political pitches. While my child is in their custody they have a responsibility, right? Or would you be OK with Cindy Sheehan coming to visit your kids' school assembly, talking about how illegal the Iraq war is?
But the right to protest on public property, without trespassing or otherwise violating ordinances currently in place, is what is being outlawed in Kansas....and the reasons are exactly what some of you state- Because we don't like what, and how, they're protesting.
Remember this when someone decides they don't like what you have to say, and how you say it.