Irish Moss needs to be in the boil. Use gelatin to clear after fermentation. Put about half a teaspoon of gelatin in some water and let 'bloom' for about 30 minutes, then heat to about 170 F (when bubbles start forming in the pan), then add to the fermenter. If you use only a few ounces of water, it's not necessary to cool it. It's the same stuff you buy in the grocery store for making deserts; just make sure it's unflavored.
If you can't get corn sugar, use regular table sugar for bottling. I use it all the time with no problems. I can't understand why everyone says to use the more expensive and harder to find corn sugar for bottling.