We 10manned MC at 70 in DA...it took so long to kill Garr that the corehounds around him respawned on us TWICE. Trash doesn't scale in Raids but the Bosses do; Garr was lv Skull to our 70s, aka +3 to highest raid member, aka 73, scaling his HP appropriately, and damage somewhat-appropriately; we did have to keep the tank healed but it wasn't the same "relative" damage it was at 60.

It would be POSSIBLE but it would take forever and the Pala's mana/hp battery seals would be an absolute necessity for the raid, possibly an spriest too. You'd kinda want a decurser around too if some of them do land on you and they probably will...and if you want to fight rag obviously you'll need a 2nd group to douse enough Runes, assuming you have the Quintessences in the first place, which requires semi-clears to get as well..lol