You pose a number of questions concerning the Orthodox form.

First, how does a catechumen discern his patron saint? As far as I know there is no single, formulaic answer to this question. Patrons are normally chosen (or are given the opportunity, if you prefer, to choose us) in consultation with one’s priest and based upon an extended, prayerful reading of various saints’ lives, in which a specific affinity may be noticed.

Second, how acceptable is it within Orthodoxy to see all phenomena as manifestations of the Logos and therefore as possessing what you called a “derivative sanctity”? This is not merely acceptable; it is the sine qua non of a genuinely Orthodoxy understanding of the created order. While the Orthodox vision must be sharply distinguished from a Romantic or sentimental appreciation of the natural world, in which a merely passionate pleasure or delight remains uncorrected by ascetic discipline, this discipline or rigor exists precisely in order that the “doors of perception” might be “cleansed” and the radiant presence of the Divine might be encountered in all things. You might usefully read, or reread, a short section called “Through Creation to the Creator” in the chapter on “God as Prayer” in Kallistos Ware’s Orthodox Way.

Third, what should you anticipate when it comes to specific spiritual practices? This is a large question, obviously, but what I can certainly say is that every Orthodox Christian is expected to have a rule of prayer, given him by his spiritual father, whether pastor or otherwise. As for the level of interiority and intensity this practice involves, this will clearly vary from person to person, depending in part on whether his temperament is more jnanic or bhaktic.