Re: Would've worked much better as a book-musical
That's true - one of the original critics commented that there are more drinks ordered during the show than during the interval.
That said, I'm glad ALW was still making the effort to set the entire story to music. Book musicals now always feel like a compromise to me - the introduction of the sung-through musical has raised the standard (when done well) and the challenge for a modern composer of musicals is to try to tell the whole story (or at least the vast majority of it) using music without falling into the traps you identify in your original post.
Yes, in Aspects there are too few musical themes, which means there is excessive repetition and occasionally the themes don't fit the character. But hey, this is ALW, what do you expect. The answer though is not to make it a book musical, but to make it a better sung-through musical.
(Despite the above criticism, I still think it's a very good show.)