I've instanced this group through almost every instance on my way to 70 and took my melee group (see sig) into Setthek & Mechanar last night for the first time. Their gear is completely made up of quest greens/blues, so the general whooping I received didn't surprise me too much. I finished both instances after many, many deaths. Better gear may alleviate most of these problems, but I wanted to see if you guys have some strats to deal with these mechanics:

Seth - When you kill prophets, the ghost goes after healer/melee. I tried to stay mobile with the group, but that didn't seem to help me much. Someone almost always bit it. Eventually just burned the whole group with the melee (prophets last) and ran away when one died.
Seth - Last boss. As much as I tried, I could not get all of my guys out of range from this thing. Same would be true for the bloodfurnace end boss. The only way I see this working in my current setup would be to use a separate set of movement keys for the dps & tank. This way I could pull the DPS out before the tank and only have to worry about 1 person when the warning comes up on the screen.
Mech - Tinkerers. It's sad that these were the guys I feared the most in the instance. All the strats I've read involve ranged DPS ... which I don't have. These guys pummel all of my guys at a pace that my chain heal can't keep up with. Send the tank in by himself till those guys are dead?
Mech - 2nd boss. From what I've read, this boss is just a pain regardless. I ran around with fire resist aura backwards kiting this boss and for the most part it worked. The major difficulty I encountered in this fight was trying to put my healer in a place where she wasn't under attack & still in range of my group while they were kiting.

I expect to take my licks while learning these instances, but would love to know if there is something major I'm missing so I can correct it before the eventual 70/80 heroic runs.