I'm fairly certain what I'm about to say is the same for loading luggage onto the ship, but I've never witnessed it:
Once houskeeping crew members have your bags on the last night, they're loaded into these big steel crate thingys on wheels. Once the crates are full of suitcases, they're taken down to deck one (the main passage for the crew to get around on our decks) and strapped to the walls & there they wait to be unloaded to the dock for guests to pick up when they debark.
So, I would for sure not put anything potentially breakable into your luggage & carry on & off by hand..
On a side note, the crates with luggage in them really help break your fall on your way back to your crew cabin from the crew bar on the last night of a cruise when the stabilizers are pulled in & we're haulin back up to Canaveral..