Most of those settings are rarely discussed because no one ever uses them. There are settings in ThrottleStop that try to cover the last 15 years of Intel CPUs. There is no need to touch a lot of those settings if you have a recent CPU. You only need to adjust something if it makes your computer run better or solves a specific problem you have.
In the FIVR window, the Min / Max Cache Ratio lets you adjust your minimum and maximum cache speed.
The Memory DDR box reports your memory speed and the microcode box beside it reports what microcode version your CPU is using.
Checking the Sleep Defaults boxes will reset your voltage and cache ratio just before your computer enters Sleep or Hibernate mode. The voltage and cache ratio will be automatically restored to your requested values just after your computer resumes from Sleep or Hibernate mode. Some computers will hang when resuming from Sleep if your undervolt is set too aggressively. This feature can help prevent that problem.
Checking Thermal Velocity Boost tells the CPU to slow down 100 MHz when it reaches 70°C. I do not think your CPU uses this Boost feature so leave it as is.
Checking V-Max Stress also lowers your CPU 100 MHz if the voltage is set too high. You are undervolting your CPU so you are never going to have this problem. Leave it checked.
Checking Ring Down Bin forces the CPU cache to run no faster than 300 MHz less than the core speed. If your core is running at 4000 MHz, checking this will box will limit your cache to 3700 MHz. Your CPU does not support overclocking so this feature might not apply to you. I recommend leaving this checked as it can help with stability.
AVX Offset lowers the CPU speed any time it is running AVX instructions. Your CPU does not support adjusting this value so it is gray.
The mV Boost feature increases the voltage but only at low MHz. This can help with stability. I think you need a 10th Gen or newer unlocked K series CPU to use this feature.
In the Turbo Power Limits window, there is rarely a need to check the TDP Level, Power Balance or PP0 Power Limit boxes. Some of these features were potentially useful when I was playing around with a low power 15W 3rd Gen U series CPU. I would like to remove a lot of these features from ThrottleStop but as soon as I do, someone will finally contact me and tell me that they actually use some feature that I just removed. That is why ThrottleStop includes a lot of features that you do not need to touch or worry about.
Checking the Speed Shift box will enable Speed Shift Technology if the BIOS has not already done so. This will also send the Speed Shift Min and Max values to the CPU.
Setting Power Limit 4 to a value of 0 disables this power limit which I highly recommend doing.
Why are you limiting what looks like a 45W CPU to only 30W? Go fix the cooling problem you have so you can run your CPU at its full rated speed and power.