If i have to say one advise in this situation is run in cover, go hide somewhere fast, it's all about tactical advantage.
I have been many time in situation of fight etc even once some people who had air soft gun, i can tell games like XCOM are very good to represent this kind of situation.
Specially when the situation is asymetrical, in restaurant or concert room, people are totally exposed, after it's about hyper vigilence thing, seeing where there are exit where they can be place to hide.
The best advantage you can have is that if they don't know where you are, they can't shoot you, and as long as it stay this way, you don't risk anything, and the best is you can be behind a door, or in a corner, you can win some fraction of second of reaction time that are what make the difference.
But if you are taking any risk, you are doing it wrong, staying in the middle of a square or in a concert room without cover like this while they have a gun, the tactical advantage is on them 100%, if you are hidden , and they can't see / shoot you, already it turn the advantage, it's always like this that need to do. Always stay safe and make sure you are not exposed and that in any case you are going to have the advantage in anything you do. Otherwise just go away and find some place to hide.
To hit someone with a stick i'd say hit sternum it cut the breath and will paralyze the person, with a knife at the base of the neck, or with punch hit the nose =)
Even if people have gun it doesn't much anything, if people are in a concert and in the dark like this, even the time someone understand what's going on, and if the people are really trained they will still stay everyone to stay calm and already being in position to control everyone move etc, even with a gun you are fucked already and then it mean what if you take your girl friend to a restaurant you need to carry a gun and watch every car that come up with a finger on the trigger lol it's bit weird .. lol
Plus there with kamikaze with explosive belt kinda even more dangerous to even get close to the person lol Unless you want to be like ok red thread - blue thread ??? :D I guess they have to press a button or something but idk ..