Good questions, but before I answer them, just a warning: you will find a 10 gallon nano a very difficult tank to maintain. Things that take days/weeks to ruin a larger tank will kill everything in such a small system in a matter of hours or a day, so you have to stay on top of the system continuously.. Now to your questions:
- 1. Do not use the crushed coral, it just traps debris. Get some sand (it doesn't have to be live, just good reef sand) and use that.
- 2. Purchase a small piece of live rock - that will serve as the seed to convert our dead rock into the live variety.
- 3. You don't need a refugium/sump, but it couldn't hurt - it will increase the water volume of your system, making it a little more stable. You might consider keeping macroalgae in the sump.
- 4. To start the tank get everything set up, fill with salt water. Then go to a local supermarket and buy 1 cocktail shrimp (my place just gives me one since the paper he wraps it in weighs more than the shrimp). Put the shrimp into fine netting (a woman's nylon stocking will work) and suspend it in the tank. Leave it there until you begin to see the levels of ammonia rise, then remove it and discard. Continue to measure ammonia, nitrites and nitrates until the ammonia and nitrite levels fall back to zero. At this point the tank is cycled. Some people then do a water change, but imho it isn't necessary.
- 5. The bacteria in your current tank are fresh water varieties, and won't help you new salt water system.
Good luck, and keep asking questions.