Please, could you remove the part of the mail you are not responding to and just keep the relevant part?
Whatever the features and syntax, you can always shoot yourself in the foot.
I disagree
Hmmm... I have succeeded in shotting myself in the foot with possibly every feature of every language I have used. This is called experience... in the end you do know how NOT to do things:-)
- some concepts are more robust, other less.
Sure. The use-case under discussion is about ONE session variable holding an expensive to compute security status which can be consulted by other functions. I think that probably one can have it right with both approaches, even if it is on the second try...
The robustness in not only about content, but about code maintenance, possibility to quickly search errors or better don't do errors