Yeah, 'twas a steep learning curve. Sorry for disappearing so quickly after my matches, but I had stuff that I had to do IRL.
On the strategy side of things it's clear that PVP tanking isn't possible - just about every team will go for the person who does most damage first, then the healer. As a frost mage I can iceblock twice (3 times if the match goes on long enough) so I *should* be doing better than I did yesterday, however I need to stay close to Amberley if she's in the group as the pushbacks from damage taken are killing me even with my haste gems. Amberley is likely to be of most use in ensuring that buffs are kept up, and a little offhealing too.
That said, I threw on what little resilience gear I have and it's clearly not good enough - next week I'll try playing in my normal PVE gear as damage and crit is a lot higher.