I don't think the problem with smart is related with
It seems more that something is wrong configured within smart
Xlib: connection to ":0.0" refused by server
With the following command you can use smart without any problems? This would mean that smart is working but only in shell!
maybe u are also missing channels. what does this command say
with the command
smart channel --show
you can add somehow channels.
smart channel --add
I've no big experience with that tool and I've never used it.
Maybe there is someone around who know SMART a bit and can explain the error message. And maybe some of my adived can help u.
Good luck and let me know