1) The lawyers can say basically whatever they want, but the jurors are "supposed" to only consider actual evidence - stuff shown from the witness stand, with a few exceptions - when making their decision. I guess this is why you want a really good lawyer... he can convince them to interpret the evidence in his way.
2) The different parties can present stuff while talking (like the Lindholm emails) which aren't evidence, and it's basically up to the jury to remember what's what. Potentially very confusing, and again, I guess that's why you want a good lawyer.
If I'm wrong on either of these, I would appreciate it if someone who actually knows something about law would correct me. Very interesting, thorough, and well-done writeup!