Hi,
Regarding displaying the error messages next to the fields, it would require customization of the view files where you have the fields.
It could be done with javascript checks yes.
Regarding the fields been highlighted, that's already the case:
monosnap.com/file/lZWFKdqbVBjPUu09yMxxNnAEHy482X
It is done by adding a specific CSS class to the inputs: invalid
That's a standard class name of Joomla which normally all templates developed by Joomla should implement to highlight input fields with invalid data in them. So I suppose that the problem for that is actually coming from your template if you don't see the fields being highlighted.