Understanding Cloud hosted App Development

I am having some confusion around Provider/ Autohosted App.

Please correct my understanding of the following:

1. We cannot develop Apps on SharePoint Online which will have server side code.  The Apps developed on SharePoint online can only use html5 and javascript, not even CSOM?

2. Auto hosted / provider hosted apps can be developed on any system where Visual Studio Express / Professional / Premium/ Ultimate is installed. It doesn’t require SharePoint on the system. It however requires IIS to help us in debugging and testing

3. Auto hosted/ provider hosted app development system, even though does not have SharePoint, can still allow us to write code which will have server object model

4. We need Azure or provider hosted environment only to host the app and not for development purpose

5. It is best practice to keep the hosting environment separate from development environment

6. The only difference between Azure and Provider hosted environment is that in case of Azure, everything is managed by SharePoint while Provider hosted has to be managed by IT.

7. Auto hosted app will work equally well on Provider hosted app. A provider hosted app can be installed on auto hosted app and vice versa

8. We do not have control over the auto hosted app which is installed on Azure. If we want to unistall or upgrade, we will need to write remote event receiver.

9. We have control over provider hosted app, meaning that, IT can manually uninstall or upgrade or do it using remote even receiver.

10. Remote event receiver’s can be created either as Auto hosted or Provider hosted app

11. Though we cannot create Apps with server side code on SharePoint online, but we can launch (host) apps that have server side code, created as auto hosted or provider hosted app, on SharePoint online