Well, I've done a few runs through RFC and my setup is working pretty well. I'm still pretty low, so my methods probably won't apply in a few weeks as I expect them to evolve. However, here's a summary of how I work. I'm still using

/assist Tehtsara
/cast Nuke

I think this may work better for me because of my party makeup. I don't have any CC, so I could probably give up focus, but why change what works. I'm not sure why people are talking about having problems with the main dying. I can still target things while I'm dead and command my minions to cast on them. In fact, I rarely wipe any more, because even if my paladin dies, she's taken enough of the heat that the pull's pretty much over. Just spam nukes and rez afterwards.

I haven't gotten around to experimenting with /focus as a performance enhancer yet, but I don't see how it would be an improvement. Either way, I have to target something with my main, then wait for my target information to populate to the server and back down to my minions. I'm starting to think of just assigning /focus to a target for an Earth Shock rotation to keep casters locked down while still nuking the primary target assigned by my Paladin.