Not sure what you want to know. The basic concept of text editing has not changed with the newest versions of Acrobat. It is still only for minor editing and is not a word processor. You should always edit in the original document if possible.
I tried to move object from second page to first one, but it disappears. How do I do this?
I used a while ago your competitor and it was no problem at all.
The thing is that for some reason pdf split pages, even though my Word doc 2010 have one page and enough space either up and down.
Go back to the original WORD file. Select the printer in FILE>Print to be the Adobe PDF printer and return to the document. Now rearrange the document to be on one page. What you are seeing is the reflow done by WORD when you change printers. WORD reflows a document based on the properties of the attached printer. This reflow is an issue with folks using forms in WORD that typically look different on different computers (that have different default printers).