There is no danger before entering the boss room. There is large debris all around the room to stand on. Standing on the sand ticks for 1500 damage, so stay on the debris when possible. The most important mechanic is that the boss will periodically emit a chat bubble. When he does, everyone needs to immediately run out of range of the AOE attack that will follow. If any player gets hit by the AOE, the boss heals to full. He has an enrage timer. After the AOE, he will teleport to a random location in the room (or the same one) and do a large low-DPS AOE attack until engaged in melee. The other mechanic is that he will throw out bubbles around the room, which will explode doing a knockback and silence after a few seconds.
The damage output by the boss is relatively low, so having the tank go mostly DPS is fine. Solo healing is a credible option. The only thing to be really concerned about is reaction times in running away from the AOE when the chat bubble appears.