These two aren't exactly bright. When they realize they're in the future they don't say "Oh, I see - I've traveled through time" they don't seem too bright. On the other hand, why were they in charge of the machine on the ship if they weren't that quick on the uptake?
I guess they were trained to handle the ship's electrical system, and turning this gadget on and off fell within their competence. On the other hand, leaving all that glassware exposed was just asking for trouble.
It's also fair to say that, as a highly classified experiment, the characters simply weren't told what the machine does, how it does it, or even how to operate it under all circumstances - more or less limited to "keep these gauges in these areas by using these controls." Granted, this approach tends to turn into a fierce butt-chomping when stuff goes wrong and the operators don't know how to take corrective action (as seen in the film, no less!) but for a situation where security beats practicality (or an abundance of "it can't go wrong" mentality), this would be a plausible answer.
Forgive me, but this poor east coaster has never been to Nevada or California, but I do know the temperatures and climates are different according to mountains deserts and seasides, etc. In the film, it's snowy in Nevada, but then it's sunny and pleasant in California. Is that normal?
I wondered the same thing. Southern California does look pretty mid-summery while Utah looks more like late fall or early spring. But IMDb says, "The live-action scenes were shot in eight weeks.", so I guess they didn't film them months apart. If it helps, remember the vortex was causing wacky weather over a wide area around the base.
The Southwest has a more varied climate than most people give it credit for; although the general impression is "sand, and lots of it," you can find examples of most North American biomes there with only a few exceptions (no boreal forests or tundra, sorry). The Sierra Nevada mountain range has areas of near-year-round snow, and if the preceding winter had had unusually heavy precipitation, snow can stick around even in lesser elevations for long enough that the two filmed sites would be possible as shown. (Even in the height of summer, the temperature differences in the high desert between night and day are extreme; while daytime temperature can easily exceed 100 degrees Fahrenheit, at night the temps can drop to near-freezing. It's not a place for the unprepared.)
Herdeg does try to check in with the Navy early on, but after the run-in at the cafe he switches to 'on the run' mode and doesn't try again. The doctor at the hospital might have thought Herdeg was crazy, but didn't doubt that there was something very strange about his friend, Mr. Sparky.