1) No need to cycle it on and off. It is, as Stevesmi said, in your food and I said - in our bodies.
2) Keep it to 5g a day. No need to load etc etc
3) Some of the gains are water. More so with the monohydrate version (hence that name).
4) Read Visions recent 'creatine simplified' post. It boosts the action of ATP and pulls water into the cells.
Now if you just use it, 'fill up with water' and stop using it - then sure gains will disappear. However, if like all PEDs, you up your training a little and nutrition etc is adapted while you use then some muscle and strength will be added / increase. So, again like PEDs, if you stop using it you should lose SOME but also keep some.