I once saw a woman standing all alone the wild, and when I approached to talk to her (almost melee range) she said GOTCHA!! and started attacking me. 2 other vampires ran up and helped her. I was like WTF. Vampire ambush.

I've had a few of those attacks before. Once when I was a low level starting a new character a Nord just came at me from behind with a power attacked War hammer, he took 3/4 of my health away.

Only had this happen once in 200 hours gameplay, but I fast travel too much which is probably why!

Yesterday I got attacked by NPC named "Redguard"
I couldnt believe it when i saw it, but he had dragonplate boots
And I never crafted any dragonplate or dragonscale armor

What are you doing out here milk-drinker go home to your mother, yeah it's insulting and they have to pay for it.

Pretty sure the loot "levels" up with you I found one of the mercenary's walking along the road in full dragonplate except the boots

I once had 2 dragons, 2 giants, a mammoth, a group of bandits and a Necromancer all involved in an epic battle in which only a bandit survived.