I've finally completed the Ultimate Heist quest on my new character! This time I was careful to head back home and dump all of my excess inventory before using the Arrow of Extrication, and to keep a saved game from just before using it.
At first I wasn't thrilled about having to start a new game, thanks to accidentally breaking the Ultimate Heist quest, but it's worked out fairly well after all.
I'm going to keep my saved game from just before using the Arrow of Extrication, in case I ever want to try to steal everything in the palace and library, just to see if there's any interesting loot.
When I first arrived in the guards' room at the palace, one of the guards woke up and attacked me as I was trying to sneak toward the door, because my Sneak skill was still rather low-- in the mid 30s, I think-- so after I restored I was careful to stay well away from the sleeping guards, despite my curiosity about what might be in their storage chests. I think I did check some of the containers in the next room and grabbed a few things, but I was afraid to hang around too long near the guards, so I quickly moved out into the circular corridor.
I did steal everything from three of the bookcases in the library, but a couple of monks were downstairs reading (with blindfolds on!), and I wanted to avoid them because I'd just had to restore a saved game after a monk on the upper level noticed me and attacked. One of the monks who was reading on the lower level actually bumped into me repeatedly as I was sneaking up the stairs, since I was sneaking slower than he was walking; but he just ignored me, and I finally had to jump over him to let him pass! I could have gone back down at that point to clear out a few more bookcases, but there hadn't been much of interest in the ones I'd already cleared out, so I continued on.
When I got to the Imperial Battlemage's quarters, Evangeline Beanique saw me and attacked, causing me to reload again. I then managed to unlock the door and quickly move away before she saw me, and lurked in the shadows directly across from the door, hugging the outer wall of the corridor since there's no alcove at that spot. She eventually wandered out into the corridor, stopping and standing right beside me for a bit-- which was pretty nerve-wracking, although she never noticed me-- then she finally wandered down the corridor far enough for me to quickly sneak into the Imperial Battlemage's quarters and escape.
I never did use the Boots of Springheel Jak, so now I've got those to play around with if I ever feel so inclined. I did have to jump off the bridge connecting the Arcane University to the Imperial City several times to increase my Acrobatics from 44 to 50 before I was finally able to jump up to the level where the switch is that opens the door leading to the next area. But when I escaped down the flue in the Imperial Battlemage's quarters-- without the boots on-- I lost only about half of my health, whereas I'd been expecting to lose a lot more.
By the way, after you activate the Glass of Time, the quest marker points to the sewer grate in the Arboretum, but it's actually a lot quicker to go outside the Arboretum and use the sewer entrance (or "South-East Exit") that's just north of the Arcane University, because that lets you avoid a lot of the vampire-ridden South East Tunnel. Not that it's difficult to get past all of those vampires; it's just a hassle to have to laboriously wend your way through the maze of the South East Tunnel. Taking the South-East Exit into the sewers lets you bypass all of that.
