When most people recommend the use of live sand, I believe that most are NOT talking about the pre-packaged sand that has the live bacteria. True live sand has bacteria and a variety of desirable creatures that will be helpful in your sand bed. The pre-packaged sand only gives you a head start with the nitrifying bacteria. That would shorten the initial cycle a little in a new tank. If you are converting from a CC substrate, your live rock will have more and better bacteria than those expensive bags of sand. Put in dead sand and either top with some true live sand, or make some baseball sized bags from your crushed coral bed using panty hose material. Place these balls on your new sand and push them in an inch or so. Leave them in for a week, then remove one every couple days. The idea is that all of the little creatures in your CC bed will come out of these balls and move into your new sand. This dramatically speeds up the transition from new dead sand to live sand.
When I changed my CC out a week ago, I did not rinse the sand, leaving in the very fine sediments. I also did not use any mechanical filter. My water was very cloudy for four days and was truely clear only after a week. I put my live rock back in the first day, using the braille method because I could not see what I was doing. I figured I could rearrange it later, if necessary. I left my corals out for three days because of the extent of the cloudiness. I had them in a large rubbermaid tub with a heater and powerhead. The snails, brittle star, and conchs I put back in following the rock. As Debi said, the sand does settle on the rock, corals, everything. Use a turkey baster to gently blow it off. Of course the water gets cloudy again, but it clears more quickly each time. As she mentioned, the bacteria or some factors of the bed will eventually cause the sand to stay in place unless something significant moves it around. Good luck with it.