If the structure of one or more table(s) need to be updated, do I just manually add/delete those changes inside the MVC files?
Form field auto update
If I want to create/edit a record, I key in the value in field A, I want field B display the appropriate value that based on what’s in field A. Do I use javascript (modify the _form.php and model file?) to handle this?
Answering your first question, when there are changes on table structure,
I usually change it at model file. But because I usually because I want this field in my form and I want to show it too, I update my view files too (especially _form.php, _search.php, sometimes view.php, _view.php and admin.php)