[Groan] Another fascinating board to become sleep-deprived over!
Most emphatically, I have had dreams that are very clear and unequivocal, that they are telling me something important.
I don't know if there are distinct levels, as much as varying degrees of awareness, but did you ever find yourself waking from a dream only to find you're in another dream, wake up from that one to yet another dream, then find yourself in bed, wondering how you can tell you're finally in the physical? Quite amusing when that happens.
Sometimes I do bump into "passed over" loved ones, including those who have watched out for me for a long time. Good to have companions along.
Have had some adventures that might border on astral, very lucid.
In general, I prefer to "do" dreaming rather than interpret symbolism. The key is to be able to share the dream with someone, ideally a loved one but a journal is fine (I never had the discipline to stick to it). And, assume that dreams are REAL, and you have FREE WILL in them, and you can CREATE a new reality every time you dream.
Went to a lecture a few years ago on dreaming, and took exception when the expert said there was no free will in dreaming. He was right in a way -- if you assume you have no free will in dreaming, then none will ever show up. If you assume you do, well, sooner or later, you'll learn how to exercise it.
Woops! Bedtime! Happy, no, JOYFUL dreams!
Blessings,
Aronaya