Are there any architectural reasons why it would be a bad idea to develop a standalone web application that uses SharePoint Online as the data repository?
We'd be looking to leverage a lot of the features that SharePoint has to offer, e.g. document management, security, workflow, etc. but we'd still need the standalone application because the rest of the features required don't match anything in SharePoint and it will be a public facing site.
My concerns are:
Authentication - The application would consist of internal users who would have SO credentials, Partners who would not have credentials and individuals who would also not have credentials.
Interal - these users are fine and would be able to manage documents and processes directly from within SharePoint as well as the application
Partners - we wouldn't want these to have direct access to SharePoint only the application but they would have access to specific data in SharePoint (e.g. documents, reports, specific lists, etc.)
Individuals - same as partners but more restricted
Best practice - Does it make sense to architect a solution like this? The alternative is to simply build a standalone application and custom code features such as document management, workflow (WWF) and so on.
Performance - Microsoft shows no interest at this stage to have data centers in Africa so we do suffer a bit with lag time. It's not massive but I imagine Asian, American and Eurpoean SO users would notice the difference.