We are few and far between in this city, it would seem, but we do exist! I don't typically railfan in town, other than a few of the spots you guys have mentioned. I drive over the Lamb Blvd. overpass every day on my way to/from work, so I always try and check things out. I've never been bothered when checking out a train there either, but I never get too close.
I generally head out towards Erie (off of I-15 near Jean) or Kelso (the restored depot, now the Mojave preserve headquarters at the base of Cima Hill) to do my railfanning. No one ever bothers you out there, and the scenery is so much more dramatic.
Besides railfanning the LA&SL, I am currently working on my 4th HO layout, which is the first permanent one I have ever built since I just bought a house back in July. I model the Detroit, Toledo, and Ironton railroad, both in its fallen flag form, and in a fictional present day form. I have several videos on youtube if you'd like to check them out:
www.youtube.com/yoshaunboysup
I also have a website for the fictional DT&I, though I have neglected to update it for a while.
www.dti-railroad.com.
Feel free to keep in contact via facebook too, as I don't get on here too often. facebook.com/shaun31us. Just let me know you're a Vegas railfan!