The Rails look 'dated' these days and I think locking and removing the battery seems out of place on the trails. But there are many of us who need to remove the battery on a regular basis . . .
CSU is crown steerer unit -the upper part of a fork, that on Trek Rail is oversized to match the oversized head tube. A normal fork (without the oversized csu) looks weird, even weak compared to stock.
I think you said you work at a Trek shop, so I have a question - are CSUs' available for fork upgrades? Fox, SRAM maybe? (looks are important, but I bet it is stronger too?)
I think too steep seat angle can diminish pedaling/comfort. Try shifting weight forward or better yet, drop saddle and sit on 'whale tail' part of saddle for the tech climbs - yes counter intuitive I know.
Another big factor is the ergonomics of the various controllers offered - simple Purion Rail 5 handlebar mount, Kiox sticking out of top tube on Rail 9.7 or 'Star Wars' style controller on Rail 7 . . . everybody gets to make their own decision on which one is the best (or least irritating etc)...
I figure I paid half price retail with installation by suspension shop - and my Rail 5 was instantly transformed from a RAV4 to a TRD Tacoma truck (!!!!!!!!!) using a Toyota analogy.
I bought a used 170 Zeb and 165 Ohlins coil for my 23 Rail 5. (from a Slash with a broken carbon frame in fact) Buttery smooth and just a tad slow steering, but I soon adjusted. :cool:
There was a running change to a cheaper spec late 2021 - I snagged an early full carbon 9.7 (w/NX, Yari, Deore 4-pot brakes) Because of Covid bike shortages, I was happy to get the bike - and pay $7,500 USD at the time, ouch.
I would choose the simple and rugged Rail 7 - just like the rental companies choose . . .
https://smileybikerentals.com/product/tully-trek-rail-7-size-large-for-riders-57-61/
PS: That particular Rail 9.7 has alloy rear triangle and is NOT the latest "Bosch Smart system" by the way.
Best to take it in to a Trek dealer who can run the Bosch diagnostics and update the software etc. Big Trek dealer like Freewheel in the Cities has the expertise etc.