Yes, it's possible to read the value of a control in multiple locations without it "crashing the PC". I'm guessing you've had a bad history with computer crashes?
For indicators the questions doesn't make much sense. An indicator will always display the last value written to it. So, while you can access it from more than one location, you will only see the last value (unless it's a waveform chart, of course.).
Now, there's actually a secondary issue, which is where the control/indicator is, and where you're trying to access it. A control/indicator resides on the front panel of a VI. If you're trying to access it from another VI then you have to use the VI Server functions to get to it. While errors with the VI Server are infrequent, they can happen. Never seen a crash, though, due to the functions. Can you use a queue? Of course. It all depends on the data you're trying to access and what you're trying to do. You asked if it's mandatory, and the answer is, of course, no.
If you can provide more detail into what you're doing a more specific answer can be provided as well as tips on program structure.
