Hello. Long time, no see.
I have to constantly revise the sheets b/c I look back on them & see a few mistakes within them. I'm just a perfectionist when it comes to these things, and it's a work in progress. Unfortunately w/ the transcribing programs as you slow down (the songs) the quality is diminished a bit (why, I don't know; the software developers in these programs need to improve on this feature a bit). And yes indeed-y, I do need practice in the transcribing dept. b/c I've just gotten into this occupation in recent months, so I'm just getting warmed up.
And oh, for the chord progression, in the sheet musics from the archive I created, you can simply get the chords by observing the pattern of the left hand. It's pretty much V's style: the main chord in the left hand, the melody/magic stuff in the right. They're quite simple, actually, but magical nevertheless.
I read your difficulty in identifying the chord progressions of the songs. I've been a transcriber from scratch, and I just began three years ago or so. It really takes practice, trust me. The key is to familiarize yourself with the pitches. Just immerse yourself into the piano and soon, you will have really sharp ears.
And oh, for the chord progression, in the sheet musics from the archive I created, you can simply get the chords by observing the pattern of the left hand. It's pretty much V's style: the main chord in the left hand, the melody/magic stuff in the right. They're quite simple, actually, but magical nevertheless.
The left hand is my main priority, b/c I can hear the R.H. better, but the L.H. is sometimes more difficult to configure, or vice/versa. Unfortunately chord progressions still aren't my forté, so I have a hard time figuring out the notes at times. I also take pride in improvisation when doing VC's stuff (so forgive me if there's some things off), b/c the key is -- when covering other artists' work -- is not only piggybacking off of them & taking inspiration from them, but making the work your own by adding your own touches, especially ones that you know would make the artists themselves proud &/or do them justice.
When testing what the pitch is I either use the aforementioned virtual/PC keyboard &/or hum aloud (but try not to do it loud enough for others around to hear me, lest they think I'm strange for doing it). VC's chord progression in many of her songs are simple, but I'm also (when I'm finished w/ her) planning on doing it for other musicians, whose techniques are more complex, like Hanson, who are my favorite band.
Taylor Hanson (he's the main pianist for the group) does more Rock, Honky-Tonky, Bluesy, Gospel-like style, which sometimes has a classical influence to it [although he's classically-trained]. I'm no expert in this area, but I know that the (piano) chord progressions, notes and playing techniques are more bizarre in these genres of music.