Freedom of speech is not freedom from criticism.
I predict your answers will be: 1. Yes, and 2. Yes, and 3. Yes, BUT. The BUT will be followed by "it's not important", "it doesn't matter", "nobody cares", "it doesn't hurt anything", "it's just symbolic", "the majority wants it", "objectors only ____(fill in the blank)", all of which mean only that you don't care about the Constitutionality, you just want your way.
You do know that there are other ways to honor fallen teammates, some have been mentioned, ways that do not involve using government property to express religious sentiments. It is clearly not a matter of mean ole constitutionalists simply being contrary. It is a matter of religionists having a feeling of entitlement, they are entitled to use anything to proclaim the dominance of their particular religion.
"Though no one can go back and make a brand new start, anyone can start from now and make a brand new ending."