I feel really sorry for you to have to read such pointless replies to an interesting question. Personally I think that there should be a subsection within Body and Soul for questions and discussion regarding dreams, and I know it has been suggested by other people before, and knocked down in favour of gossip, reality tv etc. I think some people dismiss their dreams as nonsense without realising how fruitful it can be to examine them. I'm a really practical person but I still like to question my innermost thoughts, daydreams and nighttime dreams (which are all very different things, but may be different manifestations of certain of our states of mind). There are books that can help you tune into different wavelengths but I'm not sure if it is necessary in your case, as you seem to be able to do it.
I do have the ability to change my dreams but this ability depends very much on how deep my sleep is and how nightmarish the dream is. Sometimes I choose to 'sweat out' a bad situation in a dream rather than 'rewind' and give it a happy ending, just to get a cathartic feeling in real life when I wake up. Sometimes the dream is too intense to do either and I can't choose which way the dream will go (is there ever an ending to a dream?). I dream in colour and smellorama, do you? (PS I've only ever smelled nice things in dreams so far, and hope to keep it that way!)