To start with, I learned basic open chords many years ago on an acoustic in 7th-8th grade despite my short stubby fingers.

Fast forward 40+ years (though still with short stubby fingers!) as I was looking for a calming hobby during some turbulent work years I found a great deal on an MIM strat and decided to go for it, but didn't want it just for show, I want to learn more of how to play better.

The old open chords were like riding a bike, came back to me in no time.

Here's what I still struggle with:

1) Thumb positioning of fretting hand - it's always more on the inside edge of my thumb rather than the pad no matter where I am on the fret board, though my thumb starts to creep sideways further up the neck.

2) The tips of my fingers all try to curl towards each other rather than being able to spread them out over 3, 4, 5 frets.

3) The more I reach the more I angle my wrist and the more it starts to get sore.

4) Barre chords - just the ability to get a clean chord, as my index finger tends to curl as well so a true barre is sometimes hard to achieve.

I do try and keep the neck angled somewhat high as well as angled out from my body, both maybe 45 degree angles.

Is this all a matter of not building up the muscle and flexibility I need in my fingers and wrist and needing to just spend more regular time practicing scales and/or doing the "spider-web" warm-up? If so are there any other tools suggested I could use while NOT able to sit and practice?

I've searched the forums quite a bit and see some answers but nothing directly helping.

Thanks for any help provided!