This project sounds nice. Dont bother what they say about posting keys. Many of websites ask info if the website want to post it in your name.

The way it functioning is that if you want to login you must use pass..

If you make post on that website and want to be posted also on Steemit, the Steemit ask you for posting key so it could show it under you account.

Dont live in illusion that you dont need to put posting key to some website and still to be published on Steemit in same time. It would be like i post it on facebook and that post are posted on youtube without entering any login info. That is impossible.

But there is steemconnect who should read you info or whatever if you are connected to Steem as that user (using headers or cookies) and to use that info to post content instead of you on Steemit (you see? still sharing keys anyway) so we can be all skeptic about stealing info.

The safest way would be sharing button to Steemit i think or copy/paste.
You want to do it on this old way. Be my guest, i dont want to make one post two times.

In that way i want to check this new cool thing (Dplay) and help them build it on a good way and make users to have more fun.

Contact me if you need help or if i can help with Wordpress to make it good.