Not sure if this is a bug or not, but I can't place the chain link fence when there's a block above it.
I'm having this issue too. The only way to place a fence is break the block above it, then place fence and then place the top block back. Pretty annoying, especially when the top block is Reinforced stone.
Also, Code door can be destroyed by non-owner with mining laser in long range mode.
By the way, maybe add some block which will power the fences instead of connecting the cables next to it directly? Because there is no possibility of placing cables near the fence without connecting them to it.