No they are not.
yes
The time of day thing with sun and moon dragons was only a rumor. It has absolutely no effect on the breeding outcomes.
You will get a Rainbow Dragon. Hurry you have limited time!
The Leap Year dragon was a limited time dragon available in February of 2012. There were several combinations, but the most effective was Panlong+Love. It had about a 20% success rate. Leap year dragons are no longer available, unless you breed two already existing leap year dragons together.
With a ten hour incubation, you very likely have an evergreen egg.
Breed a mud dragon and an air dragon. It worked for me first time. It will help if you get both dragons to lvl 10.
the hardest dragon to get is the rare gem dragons, because some people have a harder time with different gem dragons, if any more questions just ask.
The incubation time for a rainbow dragon in DragonVale is 48 hours.
Cold and fire are opposites in the game. When you click on the dragon in the egg market, it will tell you which what that dragons opposite is. It is right above where their incubation time is.
The incubation time for the Swamp Dragon is 9 hours! ~DragonVale Support Team
Yes you can. You place up to 12 gemstone dragons, any combination, on your gemstone island at one time. Having one type does not prevent another type from breeding.
The epic breeding isle gives you a slightly higher chance of breeding a legendary dragon. More importantly, it gives you secondary place to breed, allowing you to gain experience faster, and upping your chances of getting limited edition dragons within the time limits.