Hello Dave. I would like to offer some guidance based on what I have read on other posts - that you are wanting to learn and get better. So please don't take what a have to say, as an attack, but more as a motivation to see differently. Ok?
You have a very interesting concept in trying to show through your photography the other side of Vegas. Unfotunately you do not as yet have the ability to deliver. Some of that may be technical ability, but most has to do with a lack of visualization we might say and being able to act on that.
What I see in every one of your images posted here, is typical of how everyone picking up a camera thinks they are capturing the true essence of what is front of them. The problem is that when they are looking at or showing others their photographs - they are seeing in the scene what they experienced and what they know was taking place. Problem is that noone else recognizes those things. This is totally common.
So as an example, most are your pictures are so far back that they are capturing all of what you were
looking at - that you saw with your eyes - but don't pass that information on to anyone who would view the photo image. As well there is nothing in the pics that have strong composition or content to draw someone in even if they don't know what is being shown. A conversion to black and white makes no difference in such cases.
Another common mistake is to try and create a story out of what you have photographed. I'll give you 2 examples from this set of pics. First is your comment that you wanted to keep the museum in silhouette. I suspect that this was an observation after the fact. Why I can say that is that your cameras meter would automatically recognize the large expanse in the scene and provide a correct exposure for the sky - as it did. So unless you were using exposure compensation to brighten the scene to make the buildings brighter and thus overexpose the sky --- there would be no other outcome than the buildings being dark as they are.
A second example is trying to make a story by isolating a portion of the frame and turning the rest to boack and white as in your cactus with selective colour. I would recommend not using this technique as it seldom works and is a little dated and tacky nowadays. It was common several years ago in the wedding and fashion trade. The point is to find ways through focal length selection, moving around the subject or probably most important - picking times early or late in the day to shoot.
I am not saying these things to discourage you. But to encourage you to forget about what your eyes are seeing, and instead visualize what it is about the scene that is atrracting you, and then hone in on specific elements that can help refelect that to viewers of your image. At this point, forget about technical skills and try a develop your creative skills. An example may be with your photo of the woman on the phone. Unless you said what was going on, it is impossible to tell. There is too much confusion, eyes are drawn to the blown out rocks in the foreground. So moving in tigher physically or with azoom lens would have been a good start. Not having her in dead center would also be useful. Moving your shooting position (by walking and moving your body) may provide a simpler background. Try to learn to see what is all around and behind - not just what is taking place that you are seeing with your eyes.
I encourage you to not get discouraged - and think it is great that you have an interesting concept here. Now you have the idea, just figure out how to deliver the goods when it comes to making your photographs speak to others. A good practice might be trying to figure what it is about photographers images that really hit you - that makes that happen and then see if can't find a similar success by looking for such scenarios and content to practice on. Developing creative skills takes time and lots of dedicated practice. Once you got a handle on that, you can worry about technical refinements - although that is becoming less of a need as cameras develop the way they are.
I know you would prefer to hear 'really nice puctures', but I can't say that and thought I may provide amore beneficial response in your case ---- because you have expressed the desire to improve. All the best.