Just for information: Usually, if you press "Shift+Delete" in your filemanager the selected files / directories will also be removed without going to the trash. You might get an extra warning though.
Usually keep 3-4 old backups and delete the oldest when I make a new one.
That is very wise, and I wish I had done the same... I lost quite some work when I wrote my old backup OVER the previous one, and then removed the originals.. That in itself was no big problem, but (due to my own stupidity) the backup had failed.... I've lost a lot of stuff forever.