Hi Simon,
The option you see in the PPT, is for the users to be aware of the limitations of Flash with PPT. It also highlights some of the issues you could see and ways to fix it.
Regarding the 3rd point, its a limitation with Microsoft. I did a KB on Microsoft site which says this is allowed with office 2010. Check the link: http://support.microsoft.com/kb/291875 ( refer to More information area).
Hope this helps.
thanks,
Amit