Menu key is not useless if you're relying heavily on keyboard (read:lazy to move your hand) and know what you're doing.
If you mistype (or forgot the correct spelling) something and you can move to the middle of the word (arrow type), press menu key and voila, word suggestion.
It also serve as right click in most cases.
Insert, Home, etc themselves are not useless but are misplaced these days. They needs to be layered in the 60%, we actually need standard for that. So you're right it is useless to put in that location.
Scroll lock and Pause/Break is actually a legacy keys, nowadays there is a shortcut for those, I think e.g ctrl+c for cmd in windows for pause/break
Functions keys is better off layered in the number keys, so nobody needs to stretch their hand far away like alt+f4 and Esc layered inside the ~ button (or ~ layered inside Esc)
Numpad... well debateable, you can get another numpad board for that. So doesn't matter
Capslock should be swapped with L-ctrl as L-ctrl is more used that capslock
Well, that's for me. Probably because I'm very lazy to move to mouse. It is quicker to do with most of the tasks with keyboard
Lastly the massive space in space bar needs to be shaved off, make it closer to minila air layout, with 2 fn keys replacing. Japanese actually realized this inefficiency
Majority types with 9 fingers anyway, so we need to start utilizing one of those thumb with fn key or any other thing in that space.