Flash Files
I would like to be an option to import a .swf flash file in my slide. There is a lot of these files i use in my physics classroom!

Sorry but we don’t have any plans for adding Flash support. The best workaround – as was mentioned in the comments – is to host the SWF file on another site and embed it into your presentation using an iframe element. Haven’t tested this myself but it should work.
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Harold Seefeld commented
You can use the "code" function to embed the flash (You will need to have it uploaded somewhere first).
I agree, it would be useful to embed flash quickly. It should allow flash to be used and uploaded from the media library.