I think ogra has addressed the problem with locale.
I’m not sure of the dbus issue. It looks like something related to the clipboard support in qtubuntu. I don’t see it with the mir-kiosk-apps demos, but perhaps they do something differently to your application. Can you perhaps disable clipboard support to confirm this is the issue?
I can speculate that clipboard support is something that might have broken when we dropped the “stable phone overlay”, but I really need to check with someone that knows this code better.