All fair comments, and I think it's clear that in some of these cases it's driven by my personal taste and preference, which will not be for everyone.
In my play test what I found is that my players were mostly interested in learning about the alien race that (perhaps) built the ruin they are investigating, and they spent a lot of time in-character trying to work out who these creatures were and why they built this, and trying to interpret the various artefacts etc. Completely agree that this won't appeal to every kind of player, but I don't mind that at all.
The reason I have the dice being inverted is twofold:
1: it elides the balancing mechanic, hopefully enough that it won't be obvious to players.
2: Ties in with the theme and setting- opposite numbers on a standard dice totalling seven, seven stars above etc. Originally I thought to have seven chambers as well to reinforce this but decided it would be too long for a intentionally short scenario.
I also saw your comment about the obelisk's wounds vs ap- thanks for that very useful. I will be implementing advice on this for the polish pass.