"Small dinosuars are quite easy to handle and fit into the ark"

Small dinosaurs are quite easy to handle? I suppose you have personal experience with this issue? Do you have any idea how much food would have been gone through?

What about sea creatures? (the amount of water coming down to cover the earth in 40 days would have been enough to hydraulic mine the entire planet, stripping everything down to the bedrock and leaving the ocean with about a 1/3 dirt to 2/3 water composition.) What about freshwater fish? What about creatures that require very specific environments to survive?

"you don't need every speices, it's Kinds making even more easy to fit them into the space."

If you're going to say that a kind includes all animals who can reproduce with each other, allow me to beat you to the punch and say that that is the exact definition of a species. If you define "kind" to be more basic, you're making evolution's case for it. (since in order for a few thousand "kinds" to produce the millions of species we have today, an enormous amount of evolutionary progress would have had to take place; far, FAR more than the evolutionary timescale predicts)