It does when the hashing power of the network falls, which is basically when some miners turn off their machines for whatever reason. Historically, IIRC, this has only happened once: when the Bitcoin price fell to $2/btc a couple of years ago.
Is there a balancing point to the difficulty?
The difficulty reflects the average hashrate over the last 2016 blocks, and it aims to retarget the block time to 10 minutes, it's no more complicated than that.
Right, but again nothing stops Wall Street, or the government to start pouring millions into bitcoin producing TH/s forcing everyone out unless you are super-rich and can afford the equipment to get to keep on top of it. I wouldn't be surprised if by this time next year it will require PH/s to produce 1BTC a day based on the rate at which the difficulty is increasing.
The only way to stop it at this point is to pull the bitcoin network down a few week maybe...