1. i already found petrying our units usefull, petrifying any unit in front of a mate knowing enemy is playing Mifzuna + Hermes wing's. (Afro in 2v2 or TIS(2) at the SD), i won't develop all the cases.
2. If your wish is to stalk, i don't see why not.
3. if you're a mage, Card advantage isn't a pb, Mage is the only class that can get back skills from the graveyard.
6, a rush unit with sanctu can be a pain in the a**, How to stop it ? purge and petrify, purge can deal with sanctu, but petrify can deal with more situations than purge can do, petrify is multi task, while purge is monotask. Plus, Purge is 3 cooldown.
7Petrify on unic cards ( Serka, augustus, etc) usually make the enemy remove it to put an other, especially if they have no priest, Note that those cards are costly to kill with nukes, 15 hp for Serka (if no undead wall), and 25 gor augustus.
RnG, afraid of blocks? Not sure you can crit ? Try petrify! The first product without lies! *advertiser*
PS: Post poorly constructive, much oersonal, much offensive (i removed some parts).