Basically I am considering 2 approaches.

• Using episerver as application platform (not just CMS). This means I need to create many dynamic pages interacting with external data/api.
  • Is this easy enough for most of use cases? check http://world.episerver.com/blogs/team-oshyn/dates/2016/3/posting-forms-with-episerver-mvc/. It seems to me that even submiting forms are not that simple.

• Integrating episerver site with custom asp.net mvc site with authentication and shared layout (with css)
  • This is easy but we have to maintain same layout/design for multiple sites