You must speak with the elders of your community, ask them about Serbia and what they think about you going to Serbia. This is just because I haven't seen a Jew in Serbia since couple of years ago, when I saw one. That just means something is wrong. And that is why I keep asking people, why do they think that Jews and Serb are friendly to each other, when, there aren't alot of Jews here. And that is why you must speak with someone who has great knowledge about being a Jew in Serbia. I just can't tell, I've talked to people, but, still can't tell where did Jews go. You must prepare yourself, by acquiring knowledge about hostility or friendliness of my country towards Jews. In history, yes, we were persecuted as alike. Now, there aren't any Jews to tell the story behind it all. I'm sorry to tell you this, but the fact is, I dont know about the public opinion considering Jews. So, speak with someone who does. I just don't want to see you dissapointed.
About the law on firearms, it's draconic. That much draconic, that I, once judged, once convicted, could not hold a firearm in peace conditions Though, that was not anything criminally, just for inflicting injuries.
Inform yourself, prepare yourself, and then think about visiting.
P.S. One thing I am certain of, In Serbia, you will not be attacked(verbally or physically) for being a Jew.