Thanks for your suggestions.

Need to make more info for this client's newbies on the client page: just copy the info with pictures from this your post ...

Will add these infos, when the design is final.

Write more about needed "installed keychain browser addon" and give the list of supported browsers (as sample, I use Firefox, Opera on PC or Android).

See it as a bonus for users that alredy have keychain addon installed. But I can add some infos for next release. Maybe I can found a tutorial that I can link to.

May be, if it's possible (and easy too), make embedded JS version for nextcolony API operations (work in all browsers) using steemconnect for login ...

I will have a look at it
It would make sense too, because you can't install addons under Android so easily.

also use https:// connection instead http:// because the https-only is a browser's standard now.

its on my todo list