Hi and welcome to the Dreamviews forum.

Inception is certainly related to dreaming, but being a lucid dreamer for almost two years now, I can say that many of the elements in the film were designed solely for advancement and complication of the plot. There are no such thing as "projections" as they described it; your dreams can be populated by people but they will not attack you if you realize that you're dreaming, or attack anyone who happens to enter your dream (if you believe in shared dreaming).

Lucid dreams are no different from regular dreams, except for the fact that you're mentally aware in them, conscious and able to choose what you want to do. Dreams work as a sort of sandbox for your expectations and experiences; if you expect someone to be around the corner, visualizing them and passively knowing they'll be there, then they will be. All elements of a dream can be controlled; they do not work on a more unconscious, uncontrollable level as Inception suggests.

As for reality checks, it's not recommended to just habitually do the simple motions of them in real life in "hoping" that they'll end up in your dreams: like all habits you don't think much about (walking, talking, breathing...), you'll do the reality checks without noticing it. Awareness and being mindful in general is very important when doing reality checks, which ensures they don't become a habit. You don't even need really reality checks to become lucid; the majority of my own dreams have just been from a sudden onset of consciousness, using a reality check soon afterwards to see if I'm in a dream. But they are important for confirming the dreaming state.