Sorry, I hadn't noticed the post somehow! I'm not big on comicbook tiers but a score of 5 is arguably peak human or perhaps slightly beyond, and 10 is out-and-out superhuman. 10 STR is tearing metal with your bare hands, VIT 10 means you can go for days without rest and be immune to disease, and so on.
And a talent isn't quite equivalent to D&D skills (or the old-school proficiencies), although there's obviously some similarity. There are no trained/untrained skills, it's assumed that virtually everyone can try their hand at a task and not be completely incompetent at it even if they have no talent rank. A talent represents some degree of expertise and even a single point is noteworthy. They were actually called "specialities" in earlier versions, but that seemed odd when you consider how many of them PCs end up getting!
I'm not very good at the nitty gritty of D&D scaling, but STR 29 let you lift about 3/4 of a ton I think? Which would be roughly equivalent to a 5 or 6 on Exigency's scale. Yes, Serana really is that strong... and I think I'm okay with Exigency being a little bit silly in terms of power level.