After watching all the videos put on the Dishonored website I noticed that with possession no combat occurs. I was wondering if I possess a tallboy will I be able to fight and shoot arrows to defeat enemies around me. This goes for other characters like targets, guards, and other. Otherwise looks like a phenomenal game thanks Bethesda!

Like Strifecross say me, you can't attcak when you posess someone. Your control is rudimentary, you can walk, take objects and open doors, but thats all.
For the Tallboys... I don't know.

You can't fight while possessing someone via their bodies. They are just vehicles.

Which is why I will spend good time finding a way to hijack a TB without using possession. Me wants full control of bows n arrows.