Phase through the door with her #awesome vampire powers and then be stuck inside because she doesn't know how to do it again to get out

He'd kick the door in enthusiastically and have a fun time doing so 

bends the wood to her will. pesky mortals and their doors.

Shoot it. Multiple times. Not necessarily the lock itself, mind you, and not necessarily succeeding with the whole door opening thing; he's just really short-tempered and angry 76% of the time.

blast it with a lightning strike or slam into it while transformed into a tiger 

"Kicking it in, works wonders."

Would kick it down! No questions asked, there is not gonna be a door anymore. At least not a full door.

He would run into it as fast as he could to try and replicate a scene from a spy movie and then he'd try and set the door handle on fire

She would probably eat a hole through the door

She would kick it open in the most dramatic overexaggerated way possible   

he's strong enough that he would be able to turn the handle, without even knowing it's locked in the first place. Basically he would just break the lock by sheer strength alone.