You exercise any rights you like - I'm all about that.
I personally hope you don't hold up a sign talking about the Tree of Liberty, though.
This is my personal opinion, for what it's worth:
I think that when you are trying making a point and exercising your rights, that you make 1 point - that is, go for the 1st Amendment or the 2nd Amendment. Mixing Amendments tends to muddle things. When trying to "get through" to people, it's best to keep it short, simple, and uncomplicated.
Of course, do as you like... We're still a free country for now...
Good luck at the forum!