How can I customize the QCompleter popup window in PyQt?

I have a few things for a QLineEdit's QCompleter I'm interested in customizing. I want to make it behave similar to the address / search bar in Chrome.

1. How can I limit the number of rows that are displayed?
   For example, even if there are 15 matches, I only want the QCompleter to show 5.
2. How can I resize the popup window?
   For example, I want to make the popup window nice and snug. As per the above example, I want the popup window to resize to 5 rows exactly without any showing any ugly scroll bars.
3. How can I move the popup window?
   For example, I want to adjust the vertical position of the popup window so that it's slightly below the parent widget.
4. How can I format the shown popup window's list items?
   For example, I want to bold the part of the word that is matching.