Good overview of the subject. On the subject of attributions, it’s okay to mix them up a bit, but they shouldn’t be overdone. “Said” is transparent. Other attributions are more intrusive. It’s also okay to leave off attributions altogether, so long as it remains clear who is speaking. Another tactic is to use action in combination with dialogue. (e.g., “‘I’m not going!’ John kicked the wall and punched a hole clean through it.”) My Writing Cooperative article “Who Said That?” addresses this subject.