When do I know that it is safe in the dream world when trying to induce a WILD, to move and perform a reality check?

If your visualzation skills are that profoundly realistic, then count yourself as a very lucky individual, as that is rare! But Mikka is absolutely right here, once a dream has formed, then "movement" is not something to worry about, as you will have moved into your dream body. A good test for this is when imagining the Dreamwalker journey, pay attention to the imagined body, once those imagined movements feel entirely realistic, then you know that you have entered the dream. My suggestion is to pay less attention to the visual element, and focus more on the changes in your imagined body. Essemtially, it should be really quite obvious when the dream has formed, as it will not be something you actively create, but something that feels real and distinct from your imagination. I hope that helps.

Oh, I know that dilemma! Let me first say: I'm in no way an expert, not even close. So take my words with a grain of salt! But I did have a few lucid dreams in the last couple of weeks, and in some of them I struggled with just what you describe. If you already know you are in a dream, like you did in this storm, then doing a reality test can actually ground you and make the dream more solid. At this point, when the dream has already formed around you with visuals and sounds, your waking body should not move if you move your dream body. I've made the experience that doing reality tests, whenever I feel that the dream slips or fades, prevents that from happening. And after the RT, which in this situation should obviously tell you that you are dreaming, you can ground yourself further by engaging your senses. Rub your hands together, touch something you see, spin, jump, sing, shout etc. The tricky part for me is if I can't be sure that I'm actually in a dream. For example, I often have false awakenings, I just dream that I have woken up. My dream self is in my bedroom, so it's tricky to know: have I really woken up, or is this room around me just a dream? Then I usually try to focus on my senses first: Is anything different from how it should be? What do I hear? What do I feel? What do I see, even with closed eyes? That's sometimes the first clue for me already, because I'm wearing a sleep mask, so everything should be pitch-black. And then I eventually decide that I need to take the plunge and do a RT before I risk wasting a lucid dream. If you find yourself in a situation where you really don't dare to move, maybe try that?