This map has definitely been the toughest. To make this one easier I grab the big plasma ammo in the opening and the backpack to give myself lots of grenade(BFG) shots but they definitely can be skipped. You can also grab the soul sphere through the wall but I didn't bother going for it in runs.

The exit on this map is very close to the beginning but I couldn't get a glide to work on the bars. The only skip I could find is after the outside area with all the pinkies, (where you lower wall for next area and lower wall with archvile) you can hit a switch from below to skip the building on the right side to raise the stairs early. This saves at least 5 seconds but I found it kind of precise so decided not to go for it in runs.

Had fun going for sub 2:30 on this one and am sure it can go a lot lower still.