Definitely time for a toddler bed. I have a 2 1/2 year old daughter and she flops around so much at night. I didn't want to move her from her crib because of that, plus she never once attempted to climb out of it, but she liked the big girl bed when we transitioned her. She rolled out of it the first couple of times, but it's great now. She also has figured out how to take apart the safety cover on the door knob. Try using duct tape around it so it won't come apart so easily. Might not look pretty, but who cares if it keeps your child safe. You can even get a colored kind to match his room. I don't think any 2 year old is strong enough to rip that apart. That's a cheap and easy fix that will probably work. If it doesn't, see if the gate in the doorway keeps him confined.
Something about locking his door with the hook and eye just scares me. My fear as a child was that I would be upstairs sleeping and the house would catch on fire and I wouldn't wake up or hear anyone yelling for me, so I would always fall asleep on the couch if my parents hadn't gone to bed upstairs yet. Unfortunately, my fears became reality. Even though I was asleep on the couch, I still didn't hear my mom yelling for us to get out of the house. The smoke detectors didn't work either. I just remember my sister wrapping me in a blanket and shoving me out the front door.
Another question, is he just waking up wanting to play, or is he sleep walking? Good luck, I'm sure out of the many responses you get, you'll find the right solution that works for you :)