I held off posting the details because I didn't want to tempt people without being asked.
You've got to think outside of the box on this one, Ira.
(Actually, I posted about Spotlight because a hack I used in Snowy didn't work in El Cap, but I've since learned that the original "Quit SystemUIServer" has morphed into (probably just) "Restart" [but I shut down and started up just to cover all bases].)
I did the job seat of the pants, but here are the Terminal commands that get rid of your Spotlight menu bar icon for good:
$ cd /System/Library/CoreServices/=
$ sudo mv Search.bundle/ Search2.bundle/
Follow those commands with a restart...a complete shutdown if it doesn't work.
and if you run the second command with "Spotlight.app" (no quotes) you apparently turn Spotlight off permanently.
And since the dam has been breached, this command turns Notifications off permanently:
$ launchctl unload -w /System/Library/LaunchAgents/com.apple.notificationcenterui.plist
(That command got rid of Notifications's menu bar icon through Yosemite but no longer does.)
and this command turns Gatekeeper off permanently
$ sudo defaults write /Library/Preferences/com.apple.security GKAutoRearm -bool not
(I've always seen -bool no or NO, but "not" worked.)