When I'm passenger on a long haul flight I'd rather have the crew up front read TEM handbooks than dying of boredom
You mean: Dying of boredom from reading the TEM handbooks
But also seriously: Most of this is built into operating procedures and safety factors when flying commercially. There is a given set of rules that must be complied with (e.g. weather forecast at destination _and_ alternate airport must meet the required minima) - and when all required criteria are met, the flight will be conducted. I can only recommend private pilots to look into those rules (JAR-OPS and EU-OPS in Europe) and apply them to private flying as well. These rules are the result of a very large risk assessment study made once for all, so to say! If one sticks to them, there is no need to do specific risk assessment before every flight.
Greetings, Max