Search notes:

~/.config/xfce4/terminal/terminalrc

The terminal can almost never be too big. The following sed substitition changes the default size to 200 characters wide and 50 characters high. 
sed -i ~/.config/xfce4/terminal/terminalrc -e 's/\(MiscDefaultGeometry=\).*/\1200x50/'
Change font. Add if it does not exist, modify if it exists because I believe this setting is not included by default: 
settingName=FontName
settingValue='Liberation Mono 10'
sed -i ~/.config/xfce4/terminal/terminalrc -e "/^${settingName}=/{h;s/=.*/=${settingValue}/};\${x;/^$/{s//${settingName}=${settingValue}/;H};x}"
Don't show the «unsafe paste dialog»: 
sed -i ~/.config/xfce4/terminal/terminalrc -e 's/\(MiscShowUnsafePasteDialog=\).*/\1FALSE/'

See also

accels.scm

Index