i've cloned flowering plants before, they just took longer and needed more attention. if you decide to trim, u may as well try to clone some of the clippings. As far as trimming goes, I would lose the bottom 1/3 of the plant over a week or two, and then continue trimming excess lower bud sites that aren't likely to get much light. why waste the plants resources allowing it to make flowers that won't get much light? help it concentrate on the top cola and the upper budsites that will receive most of your light.
You'll get smoke either way. It's a choice you have to make. I don't care to fuss with flowering plants too much myself. if you dont trim it, give it as many lights as possible.