I saw a random Farmer walking down the road so I thought I'd get an easy Vampire Lord perk raise..little did I know right when I got close he turned into a Werewolf..
Hahahahaa had that too, except for me it was a hunter, I was in VL mode at the time and thought he'd be an easy kill...then He transformed xD
The babbete encounter, if you talk to her, is actually her going out and finding something to eat, from what others have posted. Added with Dawnguard, among other random encounters.
As for those other ones, they're pretty random and the dragon one is actually really cool. Must have been an epic battle.
One thing I never saw before Dawnguard was a group and Thalmor and their prisoner (who had orc arrows and a bow for whatever reason) fighting a bunch of bandits.
It was kinda awesome, walking in on this 10 person battle along the road, and then destroying them all as a vampire lord.
It was haha If it weren't for my large amount of extreme healing potions I would not have survived that cause Serana was just NO help haha. I've seen the Thalmor escort before, several times. I always kill them and free the prisoner who is most often a Stormcloak lol I mostly do that to screw with the Thalmor though, rather than an actual affiliation with the Stormcloak rebellion.
Today I witnessed a small garrison of Stormcloak guards in whiterun hold being attacked by a group of Bandits. Didn't end well for either of them once I got involved lol.