HTML5 support for viewports and positions

Apologies for my ignorance, but since time is short, can anyone help me understand whether HTML5 fully supports the ability for scripts to do the following tasks?  Just point me in the right direction? http://www.w3schools.com/jsref/obj_window.asp says that while some of these can be done in Javascript using the Window object, "There is no public standard that applies to the Window object, but all major browsers support it." Is that really still true in HTML5? These all seem like basic things browser-based applications and accessibility aids would want to do, and yet the basic HTML5 spec doesn't mention scrollTo, pageXOffet, scrollLeft, etc.

* determine which portion of content is currently in the visible portion of the viewport

* scroll the viewport vertically and/or horizontally so that a particular element or range is in view, or to a particular position

* hit testing: determine which element is at a particular location relative to the screen and/or content of the viewport (For example, can a script determine which element is under the mouse pointer, or at the upper-left corner of the visible portion of the viewport, and then use the DOM to interact with that element? Since almost all user agents are already set up to do this, it would make no sense to make scripts walk through the entire DOM checking the coordinates of each element.)

* determine an element's position relative to the screen and/or content of viewport

     Thanks,
     Greg