Ok, that makes more sense.

1) Las Vegas is not a high crime city. Rather, we are the victims of some sloppy reporting. A reporter calculated our crime rate based on the population and the crimes reported by the Las Vegas Metropolitan Police Department. That word is of critical importance as in reality most of Las Vegas isn't really Las Vegas, although only us locals know the difference. (The famous Las Vegas Strip is not in Las Vegas!) This resulted in way overstating our crime rate.

2) Given the vast number of tourists we have the actual per capita crime rate is even lower than correcting the error in #1 shows. Furthermore, a disproportionate amount of our crime is pickpocketing tourists and alcohol-fueled disorderly behavior.

For a big city we are actually unusually safe, not unusually dangerous.

With that out of the way, addressing the questions:

You treat the police here like you treat the police anywhere else in America. Note that the prevalence of guns in our society means the cops are more worried about being attacked at a traffic stop than is true in most countries. (It's not that anyone would attack a cop simply for giving them a traffic ticket. Rather, bad guys are often bad drivers also and thus sometimes get stopped.) Keep your hands in view and make no sudden movements. Especially, do nothing that looks threatening. If for some reason you must put your hands out of sight (for example, to reach for something the cop requested) tell the cop what you are doing and move slowly.

In some countries traffic stops are hidden shakedowns. While at the state level this is in a sense true even here (most traffic enforcement has a lot more to do with revenue than safety) it most certainly is not true at the individual level. Do not attempt to bribe an American cop! If you're lucky they'll recognize that's what you're used to back home and tell you not to do it. If you're unlucky you just turned a fine into substantial jail time.

An American traffic stop will almost certainly include a question about weapons. If you have anything that could reasonably be construed as a weapon you tell the cop when they ask! A cop discovering a weapon will be at best an unpleasant experience. Also, if the cop tells you to do something that will put your hands near said weapon tell them again at that time and ask them how they want to handle it. Note that this is independent of the legality of the weapon. As a local it would take me a couple of days of class, a background check and a proficiency test to get a permit to carry a gun. If I were stopped by a cop I would expect him to take the gun off me at the stop and then return it, unloaded, at the end of it. If I didn't tell him I think the outcome would be the loss of the gun and the permit and perhaps charges besides.

As for killing an intruder--you're treading on dangerous water there.

You are allowed to kill an intruder that is threatening you, but not merely a threat to your property. You aren't required to try to discern his motives but neither can you ignore the obvious--killing a fleeing intruder is generally considered murder. Also, not being charged doesn't mean you can't be sued.

P.S. I've lived in Las Vegas for more than a quarter century. In that time the only crime I have been a victim of is financial misconduct on the part of the owners of my former employer as it collapsed.