100% agreed on all of those, though that’s not a surprise since I might be the one who has opened each of those issues in Base 
, or at least brings them up in gripes when they aren’t fixed.
The philosophy should be: whatever is best for the inexperienced user for the 90% use case
HPC users have to figure something extra out to get a bit more performance? Whatever. That’s the kind of user that comes from C++/Fortran that knows how to read intense API docs. Why should an undergrad get 1 threaded runs and not know why Julia is slow in order to preference the PhD in computer science doing the 1000 core HPC runs not having to add -t 1 to their build script? Why give a giant stacktrace just in case a dev might want the full thing in the future? Just ask for more when you need it (and honestly, what’s chopped off is essentially never useful… at least the {...} new stuff).
We look so much at Jax because it’s faster, when in reality PyTorch has almost all of the mindshare because it’s easier to use.