Publish Online feature is quite good, but it'll be good if we have the below additional features:

(1) Option to edit directly the contents and update the preview
(2) Option to add the viewer comments like doing in PDF
(3) Option to attach the files, usually will be as PDFs and TXT formats
(4) Option to import the comments as mentioned in (2) into respective InDesign files
(5) Option to adjust minor style elements

Please let me know, if you need any clarifications on the above given details.