The biggest thing to know for now is that the work was contracted out
Try not to feel too bad Fish! It's not on you.
I don't want to give the impression that I don't appreciate all the efforts being done to help maintain and improve the site. The fact that Zak did an indepth CPU review(and a pretty damned good one at that) in addition to what I assume was his usual workload is impressive(and I mean really
impressive not just ironical-Krogoth impressive).
Redesigns are hard, and they're always a struggle even when things go well. On top of that I'm sure budgets are tight and time is limited and all the usual constraints which go with that are in full effect. Maybe the people that were contracted to do this redesign provided exactly what was asked of them, and maybe they provided something generic because that's the best they could do. I don't know. If it's the latter, then they should get dumped as soon as the site is fully functional. Either way, the creative direction involved doesn't really concern me as much as the execution of it, and since I'm not a great frontend designer myself I probably shouldn't spend too much time talking about it. I just wanted to offer my opinion having been in similar situations. When being stuck in survival mode requires bringing in a third party who ends up just not being capable that's often a difficult choice, but if it seems like it's just not working, then you really are better off without them.
At the risk of overstepping even further, let me also say that preserving the historical content of the site shouldn't ever have been in question. ETL is a required component in just about any move from one platform to another.
I will say that moving away from a custom CMS is almost certainly a good idea. That's a lot of overhead that doesn't really need to be there. 20 years ago it could easily have been required, but now you can reskin Wordpress, or Drupal, or Django, or any other well known platform however you like, and then write plugins to do the things it can't do out of the box.
Do not meddle in the affairs of archers, for they are subtle and you won't hear them coming.