Case #1 -
Not guilty. As much as this sounds like premeditated murder, the accused has not mentioned how they died or what he killed them with. No evidences mentioned which directly connects the accused to the victims; one of the victims so happened to kill the wife of the accused, so emotional and mental instability is plausible (which can be backed up in the statements of the accused - just because you thought of murdering someone does not mean you will/did commit to it.)
Case #2 -
Not a binding contract. eBay's bid policy mentions real estates and motor vehicles as a part of "non-binding." Therefore, it is a non-binding contract.
Case #3 -
Not obligated, non-binding contract. The definition of a binding contract is an agreement by
both sides and is legally obligated to be fulfilled
ONLY when the offers are the same as when confirmed - in this case, the agreement was a Toyota Prius XW20 for $10K. The seller came with a toy Yoda instead of the agreed Prius, and since there hasn't been any contracts signed or legal agreement, no need to fulfill your end of the deal and you can pull out any time - even if the Prius was offered on the scene.
Case #4 -
No, no contract exists. The US company owner was being vocal in the phone call about not accepting the offer (7th of June), and Alexander got the express-mail of acceptance on the 10th. Despite not opening it, it was evident from the past alteration that the US company owner did not want to accept the offer. Since he hasn't heard of him for nearly 3 days, chances are Alexander already looked for other companies, which in this case is the Japanese company, already accepting it. There hasn't been a two-way agreement or any direct confirmation that Alexander accepts working for the US company. Therefore, no legal contract exists.
Case #5 -
Yes, it's a valid written contract. Whether or not the $5 was used to confirm the deal, how drunk the parties are or what the waitress heard, a written agreement exists no matter what. If verbal testimonials matters, then they could've used Alexander's earlier deal on December 21st 1953 against him - which obviously isn't how the court of law would work. Legally speaking, George is obligated to purchase the house and Alexander has to oblige.