I think you are probably more concerned with salmonella than with un-fresh eggs. It has been a while since I had chickens but I think you are safer with a small flock than with eggs from a factory farm. Be sure to wash the shells before using, a little bleach in the water would help. Salmonella is quite sensitive to mild disinfectants, including simple things like a dilute bleach solution. Just do NOT wash until you are ready to use, if you plan to store them for any length of time.
PS - I LOVE tiramisu!!