D+ computer security policies

under D+ advanced options is security policies. Within that is the “all applications” policy and it is set to “custom”.

what does that do exactly? is there a benefit of having that policy used? what about removing it? basically I want to know how much different D+ will work/function with or with out it.

Additionally, under image execution control settings>files to check, will making it all executables (exe, dll, bat, ect) be beneficial or overkill and will it affect system performance.

Thanks

Ever find any answers to these questions?