Thanks for the tips! It's really interesting going back to that point of indistinction in these languages where even the proximity to old English is so strong. I've been hoping to try and read some of the old sagas in the process, but that's probably a bit too far back -- I'll have to see if there are some good century old translations thereof, as you suggest.

The phonetics, on the other hand, are presenting some challenges...

Yeah, the phonetics can be far harder. I struggle to even make out discrete words in spoken Dutch despite finding it quite easy to read.

For Danish, it's so similar to Norwegian it's a lot easier, but there's an old Norwegian joke that Danish is just Norwegian spoken with a potato in your mouth... To us, Danish sounds like they're failing to enunciate every single sound...

Incidentally, pronunciation got a lot easier to me when I started looking at mouth placement of natives when speaking. Just watching and copying mouth placement and movements have fixed so many pronunciation issues for me that no amount of listening and repeting could address.