1. ULPS puts the second GPU into 'sleep mode' during periods of 3D application inactivity. It saves power and the temperature and other values should read 0 until it wakes up. You do not need to disable it.
2. What you have described sounds like a CPU bottleneck. Not much if any performance improvement and low GPU usage. At the resolution you are using, this is not a surprise. You can alleviate this bottleneck somewhat by doing any of the following.
1. Using the fastest compatible system memory with your Motherboard (DDR3 2400MHZ?)
2. Overclocking your CPU to allow the GPUs a little more headroom to stretch their legs.
3. Use a higher resolution or image quality settings (Ultra preset?) to move the bottleneck from the CPU to the GPUs. You can use BF4's resolution scaling if your monitor is already running at the highest possible resolution.
4. Sell both of your GPUs and buy an RX 460 or an RX 470. This will offer better value and performance than the current GPUs you have now. You will get better performance.
And BF3 and 4 give the best scaling, almost 100% with my setup.