Jacob's Ladder is the hardest one to play as a band. That middle section is murder on drums (and keeping the rest of the band in sync). When I was auditioning drummers, that was the one that separated the men from the boys.

If a drummer could play his way through the pattern and provide a solid timing reference for the rest of the band, that's all I needed to know.
On guitar, the tab you gave is the right one, and that is the way I saw Alex play it on the R40 tour. I do it a little bit differently since this is the way I learned it, and though my way seems less comfortable, it was more in line with the fingering I use to practice scales so it feels more natural to me. However, my fingers are killing me at the end:
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-----------7----------7---
---7-9-5------7-9-5-----7-
-5-------9---5------9-----
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The hardest for me is the bass pedal sequences during the "clouds prepare for battle..." intro as well as the aforementioned middle section. That section is also a good exercise for picking dynamics. I cannot use a volume pedal since my feet are already busy on bass pedals. The problem is most drummers need to hear the picking pattern pretty clearly so I generally don't mute it enough in the early part. The "Exit... Stage Left" version is gorgeous in the way Lifeson controls and brings in his picking dynamics.
I uploaded a video from the same show of us doing Jacob's Ladder, but we never shared it publicly since there are too many flubs. I don't have any good live performance videos of that song in 30 years of playing it, it's that hard as a band. I don't think any of the bands I have been with ever pulled it off well. This is as close as we could get it.