Since we never know what will or won't work on Office 365 on a given day, I thought I'd outline a few things that we know at this time.
- SharePoint Web Services (this includes REST [OData]) are blocked.
- Sandboxed forms (forms with code) are slow to load.
- This includes forms with qRules - I ran some test with only a line or two of code in a form, and found that load times were inconsistent and surprisingly slow even with only a little code