Thank you for the beautiful Volumio.
I wounder if its possible to lock or disable the (Search Plugins) Under the (Plugins Management), i want to lock this function in some way to stop my kids from testing installing or uninstalling some plugins.
Best regards.
Al
Sorry, but there is no option for that 
Check this to see how plugins search works.
Kind of hack-ish, but you may want to try to blacklist plugins.volumio.org in your router or DNS: this should prevent plugin catalog access to all devices on your network.
Or you may do same locally on each device too (/etc/hosts changes for instance).
Hope this helps.
(preventing uninstalling would be more tricky, and will prevent Volumio smooth upgrades)