In my experience (with Android) the title bar should reappear just by scrolling up a little. I've never had to scroll all the way to the top of the page to get the browser menu come show except on very short pages.
Location on page information is kept until the browser or phone recycles the memory for other uses. If the browser has to reload the page when you go back to a specific tab (usually by running other apps for a period of time), then you'll probably lose your position, especially on dynamically generated pages. But if the browser has been able to remain in active memory and so can simply retrieve from memory the page contents, it should generally recall your scrolled position.