There are much better overviews of this from Sethares and Tymoczko.

Consonance is somewhat frequency-dependent. For more, Google Critical Band and ERB.

The happy/sad idea is pretty much a high-school oversimplification. It's true for beginners, not at all true beyond that.\

It's quite rare to find music with straight major and/or minor triads with no other colours.

to add, all of this doesn’t account for music outside of that which is a direct descendant of 15th and 16th century contrapuntal music, aka the sort defined by exactly the medieval texts it pokes fun at. any fusions are outside scope, let alone entire non european cultures of music. incredibly ethnocentric and blinkered premise.