Spent around 3 hours with industry expert (aka: Dave) refining chic website / database. Learned how to create a configuration file (and why this is a good idea). Also separated material into content, admin and theme folders. This broke things that then needed to be fixed. Reviewed when data should be sanitised.
Also discussed GET vs POST vs REQUEST. Key idea: Be liberal in what you accept and conservative (strict) in what you return (robustness principle)