In your CPU screenshots you appear to be running on all 4 threads, while in the GPU screenshots you appear to be running correctly on only 3 threads, since you have 6MB of L3 cache and Monero requires 2MB per instance, you should only mine in the latter configuration.

Nothing wrong with mining on free electricity and hardware you already have, since it's pure profit. I'd suggest diversifying your portfolio a bit with other CryptoNight currencies, such as SUMO, KRB and already mention ETN. There are ways to marginally optimize your setup by compiling the miners for your own architecture and overclocking your components, but it's not worth it if you're not familiar with stability issues involved.

Getting GTX 1060's is a solid option as well, but in that case you should be at least mining Ethereum or looking into dual mining Ethereum.