xfconf-query -c xfwm4 -p /general/mousewheel_rollup -s false

The xfce terminal binds F1 and F11 to help and fullscreen, respectively, which can make using programs like htop difficult. To disable those shortcuts, create or edit its configuration file, then log out and log back in. F10 can disabled in the Preferences menu.

~/.config/xfce4/terminal/accels.scm

(gtk_accel_path "<Actions>/terminal-window/fullscreen" "")
(gtk_accel_path "<Actions>/terminal-window/contents" "")

Panel → add new items

Datetime → properties → Format: Time, then date