I tried this quest a few days ago, as whm39/blm19. And I died 3 times while being raised twice.
Listen, don't count on invisible.
I'm telling you what happened to me:
I'm in desperate need of cash (for scrolls, for armors, for weapons, for learnig cooking), and teleport service looks like a good way to help me out. So I read every posts about teleport-scroll quests in a ffxi website.
As I've got this quest already, I started with Tele-Holla. My impression is you just have to run, run and run. No dangers as long as you have invisible and sneak even though you don't have the map. Even better, I had warp with blm sub.
WRONG!
I followed the instructions here, and casted sneak. It went well, though the mine was haunted with ghosts (not mobs) and skeletons (mobs). I managed to survive. But after the first middle door, I found another 3 doors at the bottom of another wooden staircase. I started to wonder if I went the wrong way. But I can't get back then, and there's no other way. So I just go through another middle door. I kept left. But I've passed more than 3 forks (there're 2 only as instructed by the posts below), still there's no hole or jelly. So I get back to the first fork and tried the right way. It felt wrong, too.
After some thoughts, I search the area and asked for instructions. Luckily, someone came and brought me to the hole. She jumped down. I stayed and casted invisible before jumping down. I should be safe then, right?
WRONG!
1st death
Invisible immediately wore off and I got aggro'ed by a bomb. She got aggro'ed by a rancid ooze and told me to run, so I searched for ???. I misunderstood her. She meant "run to exit". So I should have ran to south. Anyway, I don't think I can leave being aggro'ed by a bomb. (Later, I learnt that bombs aggro to magic even at a far distance, so DON'T cast invisible right above the hole!). And I should warp instead of run. (I forgot I can warp before I died, as I was so nervous.)
So, I died. She frowned.
2nd death
After I got raised the first time, the raiser left me without cure, so i cured myself and casted invisible, then the bombs came. I died.
3rd death
I got another raise. He's my friend. I rested (stupid of me). He said "don't rest here". I stood up and followed him. I got aggro, and he claimed it. I ran to south, bumped into flies, got aggro. There're flies all around and THEY LINK. I died, with flies dancing above. He defeated the mob and ran. (Obviously, it's dangerous for him to stay here, even he's at least lvl 50.)
Before going back to hp, I lied there for a while, and observed people occassionally ran into the screen. They didn't get aggro. And according to my previous search, they're lvl 50+ (maybe higher, can't remember, but surely not 40-ish).
Conclusion
1. So there're 2 middle doors to go thru. Turn left whenever you're at a fork.
2. Keep sneak on. If it's about to wear off, stay at a safe spot and re-cast it once it wears off.
3. Cast re-raise, stoneskin and blink (in case invisible wears off and you won't get interrupted while casting warp), then invisible, a long way from the hole after you've found it.
4. Your mp may run out after castings or drop below 100 after you revived. So, bring some silent oil and prime powder is a good idea even if you're whm. Or bring some food that adds MP so that you can keep mp above 100 for warp. Or bring a instant-warp scroll.
5. Warp once you get aggro. Invisble is useless at that time.
6. According the posts, run along the train track inside the room for ???. You have to take a path curls a bit to the west. ??? is all the way in the left hand corner (G-8). Someone says it's on the back wall of shecd. (Check your position, if you've no map, by typing the command
. I had no time to spot the ???, esp. as I dunno what's a shed/shack. I'll update this part later).
7. If you can't warp, after jumping down the holes and got everything (or you want to leave, got aggro, whatever), head south and call for help with . There should be some high level players around.
8. I just checked the bestiary. Nearly every mobs down the holes aggro, except the sadfly (but it aggroed me). Most detect by sound, as well as, detect and pursue by scent. The bombs detect by sight and magic. The jellies guarding the hole also aggro, and detects by sound and scent. (They didn't aggro me though) So you'd better keep Sneak, Deodorize and Invisible all on.
Good luck if you're lvl 50-
I'm trying it again, with a party.