Hey there. I am only 18, but I thought I should share my opinion anyway and see if it helps.
Firstly, I'd like to say that I really admire you for "coming back to school" and considering doing VCE. I think it shows that you are really motivated and you will definitely end up in your course of choice

Having just completed VCE, I would definitely recommend it. It is quite a tough experience, and many people don't like it, but that's mainly because we do it because we "have no choice".
As a 23 yr old, who's coming back to do it for himself, I'd say you would have a far more pleasant experience. You would be more motivated, more mature and ready to handle these studies, and thus more inclined to succeed.
The benefits you mentioned are also very viable, especially about the flexibility which I definitely think is important. Cost is also a great factor to consider.
Honestly though, the issue with VCE is that it is essentially one big competition. Most people don't get the greatest foundations in their subjects because they do it to succeed, rather than to actually learn. VCE would mainly be advantageous if you're ready to spend a year learning for marks, rather than for true knowledge (That should come in Uni). If you want to get the maximum out of the VCE in your position (pretty much just the ATAR), then you mainly learn/study for the exam, not for the subject. That being said, learning definitely does happen, and if you do the right subjects, your maths/english skills will improve.
In the end, it all depends on what type of person you are, and if you are able to put the extra miles into study for one year to do well in the "competition".
In conclusion, I do reccomend it. But that's just from my personal experience... I hope others with more similar experiences can help you out
