How i can show this button?
Edit category -> Item view options -> Item navigation -> Show.
Is it possible to move towards this button between items of other categories?
NO
2) What is happen here to Go to Top and left side when i used this code?
Fixed
3) I need to center a module (someone of Bottom) inside the page. How can i center it?
You can use editor.
4) Is it possible to put a like facebook botton for every pictures inside the K2 portfolio?
NO
joomfreak