What's wrong with protesting outside military bases exclusively when they want to protest against the military? Scared that soldiers would just respond by beating them senseless is my guess, especially if the bases are away from the police forces who have to defend them.
No, the point of protesting is to raise public visibility of an issue. Protesting outside a military base does stuff all. Protesting in an urban area, and announcing it so that the maximum media coverage is available, does a lot.
Don't make the mistake of assuming that the WBC are idiots. They may have some totally messed up views on how to treat people, but that doesn't mean that they're also totally incompetent in every other endeavour they attempt.
Personally, I read in your posts the struggle to continue to be politically correct ("I don't actually want to see them harmed") against your hatred and views that they should somehow be exempt from the protections offered to other citizens ("remove their right not to be physically attacked").
I read that you'd be willing to throw away the rules to deal with this particular group, but that the rules should continue to protect everyone else. I don't think it works like that.
"I disapprove of what you say, but I will defend to the death your right to say it."
There's a reason that the Voltaire "quote" is so well known, it's because a lot of people agree with it or at least think that it's an interesting idea. Unfortunately, it's rather easy to agree in principle, and rather harder when faced with something that you actually disagree with.
It shouldn't be surprising that many people find that they actually can't do it in practise, but it doesn't mean that we should all stop trying. The WBC are just a bunch of :censored:holes with nothing better to do than stand on street corners hating on people. If that's what they want to do, and they do it within the rules designed to ensure that no protesters inconvenience others, then fine.
They win by winding you up. The correct response is to give them the finger and carry on. It can be hard, but it's the right thing, and it means that you're better than they are.