Well, most werewolves can transform at will. But the thing of it is that the person, depending on willpower, lose control and is prone to kill anyone or anything. It's instinctive for a werewolf to hunt. Imagine a starving wolf finding his prey. Of course he's going to attack and try to eat, it's hard wired into their system(Thanks to Hircine). If they don't feed, they lose health. So in a way, it's mostly instinct to kill to survive.

On Skyrim werewolves, we have a theory that they were modified by the Glenmoril Witches through a pact that they made(mentioned in game). Just as the Cyrodiilic vampires were able to walk in the sun and mingle with people while posing as humans themselves. The problem with the Cyrodiilic vampires is that if they want to be in their most prime and powerful state, they must starve themselves and risk being blood-starved and identified as a vampire since their appearance is morphed up, rendering the masquerade useless for the time being.

Werewolves in Skyrim were said to have made a pact with the Glenmoril Witches that if they hunted in the name of their lord, Hircine, they would be granted "Great power". We don't know the specifics of this great power, or what it truly is. But all we can assume is that they were given control over their transformations and do not suffer from lunar transformations. They do have bloodlust, but it's not in the same effect as the other werewolves in lore. They don't lose health by the hour, but if they are injured or near death, they need to kill a person to survive.

Of course, with every pact there is a catch. Werewolves upon death are claimed by Hircine for his Hunting Grounds. If your a Nord, I'm guessing that's a bad thing since it's rooted in their society for them to want to go to Shor's Hall in Sovngarde. Some don't mind though, they can easily to the Hunting Grounds and kill things for eternity. But I think the pact may have altered them. You think a large famous mercenary group would be running around transforming during the full moon all the time? It would draw too much suspicious. Unless they tried to cover it up saying "We have full moon meetings in the Underforge. Don't worry, Ysgramor did it too! It's perfectly normal."

Hell no. So I guess to truly have a good measure of control over Lycanthropy is to bargain with the Witches or get Hircine's Ring, which has been known to have many different properties such as prolonging a person's life(Bloodmoon), surpressing the bloodlust(Bloodmoon and Daggerfall) or giving them more transformations(Skyrim). Then of course, you would have to earn the ring. Sinding stole it, which probably displeased Hircine because it's not truly sporting. Which is why he threw a curse on it, and Sinding was trying to desperately appease Hircine by killing the White Stag. Though we all know the death of the little girl put him behind bars before he could pull off his little "Hunt of redemption."

Note: Sinding says werewolves transforms under the full moon, so he probably is one of the "normal" werewolves."

Pretty much. It's the truth, Skyrim werewolves svck compared to the others

Yeah, the series is dumbing down by the years!