Home/end are not really necessary on a Mac, where you can use cmd+arrow keys instead (left=start of line, right=end of line, up=start of document, down=end of document).

The function keys are also not commonly used by apps because the system maps them to brightness control, volume, play/pause etc. by default and you need to use the Fn key to produce the actual function key keystrokes.

The convention for incremental search is: cmd+F to open the find dialog, cmd+G for "Find Next" (which is great because it's right next to cmd+F), and cmd+E cmd+G for "search for selection". Every macOS app works that way and the F3 key will not be missed.

It's really not that bad. The only key I miss on Mac keyboards is forward delete (Del).