I encountered him once near Dawnstar and he said:
"M'aiq has heard that the people of Skyrim are better looking than the ones
in Cyrodiil. He has no opinion on the matter. All people are beautiful to
him."
"M'aiq does not understand what is so impressive about shouting. M'aiq can
shout whenever he wants."
And to answer how he survived all these years:
"M'aiq's father was also called M'aiq. As was M'aiq's father's father. At
least, that's what his father said."
I've met him twice. Once on the way to/back from Whiterun. He was standing on a hill overlooking the landscape, right off the path from Riverwood to Whiterun. The second time I met him was west of Dawnstar, in the complete middle of nowhere at the top of a mountain. He was just standing under a tree in the middle of a blizzard. Strange guy; just comments on rumors he's heard about you and Skyrim in general, and if you talk to him too much, he says he doesn't want to talk to you anymore and then won't talk to you lol.
I've seen him probably 10 times, but I don't fast travel anywhere. I have seen him along pretty much every road, even the small one from Riverwood to Whiterun. I've seen him 4 times on they road from Whiterun to Markarth. You can usually ask him 3 or 4 things before he tells you to piss off. They all seem to be related each time you talk to him, like once all he refered to was the snow, another time it was dragons, etc.
I met M'aiq many times. I will not say where I saw M'aiq... perhaps I did not. But seriously, I met him twice near Riverwood, once on the north side of town, on the west side of the river, the other time I saw him south of Riverwood, across the river and west of it a bit. A dead bandit was at his feet, and a horse (non-stolen) was nearby. I took the horse, but unfortunately when I dismount, it begins making it's way back toward the place I first found it. I've also seen M'aiq near other cities. He will talk a bit and then say something like ' M'aiq is done talking now, go bother someone else.'
I've seen him a couple of times, once near Windhelm, the rest of the times just randomly on roads and such. I don't think he has a regular schedule like in Oblivion, I think he's some kind of random encounter. Nobody ever sees him coming, and he shows up in the strangest places.
As to how M'aiq survived all these years...I think he's Mephala, Daedric Prince of lies and intrigue, in disguise. Think about it.