Rules of filmmaking (particularly stunt doubles)

Can anyone point me to sources of 1) actual filmmaking techniques with regards to editing cuts, 2) editing cuts with the advantage of stunt doubles and 3) editing cuts in general?

  1. When trying to affect a believable scene, one must take advantage of any procedure, whether it be a clever editing cut (object of death already in chest appearing to be mobile due to film cut) or identity switch (protagonist appearing to be in frame due to stunt double). What are these techniques or good sources of such?

  2. I’m watching the “Gwaine” episode of Merlin which involves a lot of jousting with knights in their full armor and helmets. I imagine the onus is significantly smaller in scenes where identity is such easily concealed. But there still must be some editing technique where identity is concealed to make the audience think a particular entity is the protagonist (or someone else). What is involved?

  3. Regardless of special cases, I’ve heard of “speaker one on left side of screen, speaker two on right side of screen” continuity sort of tactic = what are other examples of screen filming basics, or else definitive source of said rules?