Hey @thedanielart97, i think you have the right idea in mind however on the example image you gave trying to locate the 3rd Vanishing point seems to be a bit off, (keep in mind im just eyeballing it, since i dont have access to photoshop to confirm as im writing this) to me the 3rd vanishing point seems to higher than your suggested location and to the left a bit more, look at the lines for the door opening, they are slightly angled leading me to believe the 3rd vanishing point might be located elsewhere.
REGARDLESS, i agree with everything you mentioned. regarding perspective.