Well it's a start, yes, a lot of technicalities. An the fact that you alone developed this is really an achievement. 
So the video will stay on for well over 4 years, but after that if someone wants to leep their vidos on the platform will have to pay, that's a little of a bummer, but maybe until then a more permanent solution will be available?
My opinion concerning the present functionality, as you present it i would say it really needs to upload video progress bar, so you do not stay there blindly waiting to see if you piece is uploading or not. As far as the most important feature, from the ones you listed I would pick reputation system.

Well that's what i had to say about it.
Looking forward to it. So I guess i can just go there und login using my steemit username and posting key. Interesting!

Thank you for your work