My natural limb strategy with the mage room was to run in and hack them all to death with my Justifier and heavily enchanted GEF whip of thievery. The key to surviving I found was to get my AGI above 30 with boots of agility. I don;t bother with fire resistance but wear a cloak of electiricity resistance instead. You can't teleport into the octiron mage room because it is full but a valupurium pickaxe gives your easy access. I guess you could balst your way in with a wand of striking. Once youa re in hack your way to the Elder dark mages first. Telecontrol is necessary as are telewands. For the rest of GC beyond the portal I used my 100+ int (dolphins at 50 INT/WIS) to spot out the Elder Darkmages and take them out quickly, teleporting next to them if necessary.
Petrus isn't that hard to kill, I once killed him with Elpuri's Head just for kicks (not in WM and with natural limbs). I always find surviving all the Elder Dark Mages harder. Get your End up a little higher to survive a hit from petrus. Your HP was high but all the HP was in your artificial arms so your groin, torso and head are all vulnerable to one-shots. Personally I think Sherarax is more dangerous than Petrus, but maybe thats because I use natural limbs and don't get super Dex and Agi.
I do same as capristo but i have noticed that strongboxes are more explosion resistant than even golden eagle feather chests so I always carry my essential wands in a strongbox.
somewhere on here is a post about how i accidently drank a bottle of sulphuric and survived thanks to shitload of teleporting and multiple stashes of healing fluids on differnet levels.
you can wish for an angel hair whip but what you will get is arandom whip most likely ommel hair. Basically you can;t choose the material of an object you wish for just the obect class (eg. short sword, etc). If you want to wish for a weapon I suggest Vermis , Turox, or Saal thul, but if you really like whips wish for a whip of thievery (but most games you will find many whips of thievery).