Need advice with apartment wiring
If you have to ask here, you need to ask yourself, "should I be messing with mains wiring?" Do local regulations allow you to mess with your wiring?

Regardless of what's in the apartment, as long as you fuse the thinest wire correctly, the wire will be safe from overload.

What's the ampacity for 16awg? Let me look that up on wikipedia for you. About 18A they reckon if you let it get to 90C, you can guess at half that for something you can touch, say 60C surface temperature.

They also suggest fusing a conductor with a wire 4 gagues down, so 20awg. Sounds a bit thick to me. Try google for some wiring installation regulations that pertain to your area.