It's the whole screen area, so you can identify the ROTATION of the map. The direction of the door/stairs/entrance or the direction the player is facing make no difference at all. Then you follow the pattern you see on tutorials based on this rotation.

Look at this image from Nightfallx tutorial: http://nightfallx2.wixsite.com/d2speedruns/map-layouts https://static.wixstatic.com/media/8322a9_c86006a163a14c84b071ef6e0a5a031a.jpg/v1/fill/w_478,h_358,al_c,q_80,usm_0.66_1.00_0.01/8322a9_c86006a163a14c84b071ef6e0a5a031a.webp

Analysing it, we can see that the first tile, the whole purple box, is on Southwest of the map, and (probably) the map extends to Northeast, so that's the direction you should try going, because that's the pattern for Underground Passage. The exit is always going straight, BASED ON THE ROTATION OF THE MAP, or the first tile, as they say.

Of course we can see some odd maps where the exit is "behind" the entrance, but the rule is still valid,,, If you turn 4 times to the right, you'll going the same direction as you started, right? Or when the exit is 'to the left' ( of the relative rotation =] ), if you turn 3 times to the right, it 'becomes' a left, right? ;)

Let me know if this helps you. =]

Interesting thoughts. I wish I had time to theorycraft on barb and actually run it.

I may add a few thoughts:

1. Barbs can't actually skip a bunch of acts like other classes. Mobs HP will get higher and higher, and your chance to hit/survivability will get lower. So, you need to improve your gear as you advance, act by act. Items with Fast Ht Recovery, high defense (yeah, defense matters for barbs, improved with Shout/Iron Skin) and some resistances are very important. Note, consider this with the offensive items you quoted.

2. The leveling/farming strategy is quite different of other classes when going solo after Normal:

• 21/22 (ending Baal Normal with current speedrun strategy), farm Baal Normal until 30 or so. Reason: for a Barb, you'll be underleveled and undergeared for Nightmare. Baal minions provide great XP and Baal himself provides good gear. Low tier sets can provide a huge boost (Sigons, Angelic)
• 30ish, runes farm. Here we basically look for the runes to get the really useful low runewords. Amn(11)/Sol(12)/Shael(13) can drop on NM Countess and Normal Cow Level.
• 34ish to 40ish: run through NM. As skipping acts is not a reliable strategy, killing elites along the way is the best way to level until 40. Killing Mephisto a few times can provide some good gear. If you can't kill elites (or even trash mobs), then you need better gear. Some more Normal Baal.
• 40ish to 55ish: Baal NM. Again, this is the best place to get XP and gear. NM Mephisto can be done a few times too, for items.
• 55ish to the end: Run Hell. At this point, reliable upgrades are really a long shot. NM Baal can provide enough survivability (sinergizing with your Warcries) to face enemies, but you will still rely on crushing blow/unique items to deal damage. If you have enough damage, good, if not, NM Baal is the only option to farm. Just like NM, if you can't kill elites, then you are undergeared. Using some time to farm is better than run through the Sanctuary without killing anyone.

3. A few considerations:

• Stealth isn't very good after normal. Without resistances, you are an walking target. Yellow (rare) armors with resistances/FHR/high defense are more useful than Stealth.
• Charms help a lot. Any Cow Level is great to farm resistance/life charms.