I know the risks but 95 percent of the time I get an issue it's because of me mucking around too much. That is why I have system restoresDeleting these keys in bulk is very harmful IMO. You lose the possibility of troubleshooting if something goes wrong. And with lited installs especially, many things can go wrong (and you can find hints in event logs).
Instead, I set all dword values EnableLevel=3 in WMI\Autologger\*\* subkeys (that's to show only errors+warnings, which quiets them down considerably), and of course start=0 to those loggers that are not needed (nearly all of them excluding event logs).
Loosely related, I set all ErrorControl dwords in services to 0 or 1 (silent or warning during the start of service if something goes wrong). In practice, I edit all values higher than 1 to 1, and leave 0s and 1s alone.
I delete (edit) some unwanted dependencies of a service to services that are non-existent (lited) or disabled/deleted by myself (always delete a service with sc delete - that's how I learnt in the old days ). But with care, some services really can't start without their dependencies.
For network icon I use this - the windows' built-in icon is useless after Vista because it doesn't show the real traffic. And of course, because of the privacy concerns with probing.