1. By default the UI available in BPM tools is limited, and very process centric.
2. For any Human Task/Activity of a Process – you can visually create a UI in BPM Tool.
3. Many BPM Tools (like Appian) would allow you to supply your own custom JSP page for Human Task/Activity.
4. Must remember that, by and large you are not creating a Portal, but a BPM Application.
5. The default dashboards provide things like – list otf Tasks pending for that user, reports, messages etc. These can be visually configured.