I took some time to take a class for a career change and I LOVED IT, i was shocked how much I enjoyed it, but don't have the time / resources to go all in at this time.
I completely echo your sentiment about taking classes at a mature age being completely different. I was not a good young student but I found myself excited EVERY DAY for class when I was going. It was so much fun. There were a few of us older students and we were always excited with a handful of younger students.... the rest of the students looked like they were greatly inconvenienced by going to class (admittedly I probabbly did too at that age).
The difference taking classes now vs then is night and day for me.
There was a core group of us who worked together a lot showing up early / staying to help each other, and it was about 30% older and 70% younger and it was a great experience.
For context, I went to school several years later in life than most undergrads, but I wasn't a developer during the intervening years. I came into university with nothing more than a hobbyist's knowledge, but through continued extracurricular activities and paid internships, I kept myself perpetually well ahead of the curve.
1. True, and the ability to complete over-engineer undergrad CS projects just because you have the time to do so is often a lot of fun.
2. Didn't work that way at all for me. I already had a better theoretical understanding than the undergrad curriculum was designed to teach me, so I was constantly bored. I didn't even do particularly well in the theory-focused classes because tests often asked to regurgitate what the class taught rather than asking for an explanation of the theory that was the subject of the class.
3. I find this one utterly baffling. How anyone could consider studying (as distinct from learning!) a privilege is totally beyond me.
1. The hands-on subjects will be very easy for obvious reasons
2. The theoretical subjects are going to be extremely interesting to you, because you will be able to investigate the theoretical basis of things that you've learned from experience - when a subject is very interesting to you, automatically it's less hard to study.
3. Studying at a relatively mature age is actually awesome! Studying feels more like a privilege and less like a chore. And the interaction with younger students is probably not going to be as hard as you think.