You can put whatever you want on your sign or banner, it all falls under the 2nd Amendment. For that matter just show up to protest the infringement of ALL of our Constitutional rights by our government!
Pardon me but, F*ck the "backlash". It's time to go on offense and stop losing our rights inch by inch.
I say we be as "offensive" as legally possible. 
I hear ya.
And I'll show up.
But what are we protesting ?
How we gonna protest the infringement of all our Rights ?
We're gonna look like a group of anti-government crazies. Which we're not as far as I know.
Idealism is admirable. But realism can be successful.
As far as 2A ? Does anyone know of any 2A restriction bills planned for this legislative session ?
Because then we could put some focus to this.
Otherwise we're just standing there asking them not to change anything.
Are we gonna shotgun this thing and try to get all our rights back with a symbolic Hail Mary.
Or are we gonna aim with some precision and try to get one Right back that we should already have.
And win our Rights back inch by inch.
I still say CCW should be the focus.
And you're right. Anyone can put anything they want on their sign.
But United we stand.......
And backlash can be a Bitch...