Mass Items and games Bugs

There are a lot of bugs, list is very long, if i can chat with a developer and speak with him while play is better, just send me a mail, i have some suggestion for fix it. This is my bug list:
1 - NPC locked in angle of any Fence (animals, villagers, zombie ecc)
2 - Duplication of Powered Rail (for unlimited free rails) with Sticky Piston + more Slime Block
3 - Duplication of ALL ITEMS stackable with Item Frame
4 - Disappear of horse when you ride and logout
5 - Texture pack plastick sheep bug
I can show all this bugs in all public servers and no cheats worlds
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