I dug a few pages back on the forum first, yes, and I'm sure it's here but...
Regarding the first boss, I've seen differing opinions regarding whether standing in the pit or standing in the pathways is ideal. Personally, I've actually been standing on the top of the curb between. Maybe I'm just opening myself to both damages, haha, but it's quick to maneuver that way at least. Usually stand in the pit though because the fire brewing seems to be less damage. Thoughts?
The BEST position you can get is by having the boss in the pits while both tank and dps stand on the walkways. However, for this to work you need a tank who knows what they're doing.
The 2nd best option is to have the tank stand in the pits while dps stand on the walkways (preferably done with a lm who antstun the tank)
The 3rd best option is for everyone to stand in the pit... obviously this is a bad idea.
In my experience the option most frequently used is the 2nd followed by the 3rd while the 1st option is only used by experienced groups.
As for the steam dmg, you've got ~5 secs from the initial hint to the actual steam jet so you should under no circumstances really get hit by steam if you pay attention. There's also certain safespots on the walkways that you can use (steam has higher initial dmg but no tick while lava has lower initial but a nasty tick, so if you've got people who are slow to react lava is deadly)
I completely disagree with Fralin. I always stand in the squares both with my guard and my RK. You simply stand near the edge and move when the lava comes. If you are in the pathways you will take steam damage unless you move which is the same as with the lava damage. However there are more opportunities to take damage from the steam and it is harder to detect. Seeing the lava is very obvious. And even my squishy RK can survive long enough to start moving.
Having said that I guess it would depend on if you can detect the steam well enough. Either one works as long as you move.
On walkways you can get steam, while in the pits you can get lava or falling debris. While the boss is invulnerable, there is no point for anyone but the guard to be in melee range. So you have to make your decision based on what is easier for you to spot : steam vents or lava pits and adds calling for the debris. As a DPS class, I usually move between both, and look for what I am supposed to avoid when I am on either place. As a tank, I usually stay in a pit and move to another pit if lava is coming. When the boss gets vulnerable, everyone get in the pit with the tank and the boss, and we all move away together if lava comes (you won't get debris in the same pit before vulnerability expires).
Missing at the same time the lava and the fact that the rest of the group (including the boss) moves away is quite difficult. If you have someone in your group who misses these two obvious events, he is probably watching TV waiting for you to complete the instance...
For hunters I'd recommend that they stay behind the boss if they're in the same pit with the boss, or actually be one pit over at the edge of the pit/square. That way if they get lava or fire-bombed they can move quickly. Hunters and healers are very frequently the targets of the firebombs so standing away from the tank is a good idea.
Also, it's very easy to get out of the square before being stunned by falling debris. Just make sure you have buffbars as the falling debris puts a debuff on you about a second or 2 before the stun happens. If you're quick enough you can make it out of the square.
I recommend not standing on the pathways that get hit by steam. Especially if your tactical mitigation sucks and you're squishy.
To me, standing in either place seems to work fine as long as you are aware enough to move out of lava or a fire puddle. I don't find either steam or falling debris to be all that bad to get hit by, so I don't even bother asking people to avoid them.
What really bothers me is when people stand too close to where the adds respawn and immediately aggro them when they show up - especially healers.
This is an obnoxious fight to me. I can't recall every wiping on it - but it's still one of the more chaotic annoying boss fights in my opinion.
Truth is there is no safe place really to stand on this stupid fight, and you just have to move around a lot. Tying to find a safe spot where you can avoid the fire, the lava, the steam, or the boss's frontal and kill stuff at same time is like trying to find a needle in the haystack.
So my thoughts on it is just do as much damage or healing as you can till one of the booby traps do hit you then move fast as you can to get out of it - because I find that tryign to find the magic position where nothing hits you is almost impossible and takes up too much time that could be spent killing or healing stuff instead.
the steam from the wall is pretty obvious I thought. It's similar to the last boss of Forges in Moria. It does a baby effect before it actually shoots out and damages you giving a heads up to move. Main difference is instead of a consistent pattern in Forges it's random in Foundry and can come from 2 directions; but still easy to look at both places at same time and see.