Use different icon for Application panel
The currently used icon for the application panel looks cluttered when scaled to a 16x16 size. Instead of it I would suggest to use an icon that resembles 'view-app-grid-symbolic' (the dash 'show applications' symbol).
@aday suggested using 'view-app-grid-symbolic':
Another way, to keep with the circle shape of 'view-app-grid-symbolic' would be introducing a new icon as 'preferences-system-applications-symbolic':
The .svg of the latter: It is not centered, but neither is 'preferences-system-time-symbolic', so it should be fine.