Absolutely! Our man. 
Yes! 
That's funny actually because I thought that was Mark who played the guitar on When You Leave. So it was a surprise for me to know he only did a "crooner" type of thing on it. And I also can't remember any tracks where he wasn't playing the guitar, so he's right there, too. A great addition to the list of songs for sure.
It would have been interesting to see the recording of this. I bet it looked quite awkward as there’s no way that MK is used to singing without holding a guitar so probably didn’t know what to do with his hands. If you watch Paul McCartney singing “Kansas City” at the Concert for Montserrat, it’s obvious that he doesn’t know what to do with his hands.
You can see that in the Time In The Sun clip as well. He’s acting funny because he’s awkward singing without a guitar.
For me preforming without guitar is a suicide. You need something to protect you from the audience, and the best way is to hide behind the instrument, whether it's a guitar, or a piano or something. My personal pet peeve is singers who just sing and don't play any instrument... Especially when you don't have enough musicians and here's this guy, who just sings and do nothing.
Of course, if the guy has the personality of your typical non-playing frontman (Mercury, Morrison, both Morrisons, etc.) that's acceptable. But for people like MK, I think, singing without playing is almost like being humiliated.
