The extra midshipman made sense for a number of reasons, not the least of which is the mortality rate among Europeans traveling to the tropics. History is replete with accounts of ships which ended up with but half their crews left after the ravages of disease hit them.
As for the accent, it is unlikely that it would be strong, since the Baron would have spent much time at schools, etc., with others like him, who were mostly English. He is from Ireland, but not Irish, in that insidious system where there were mostly British landowners and Irish peasants.
You may be right, but I think a pardon is doable. We'll see.
We need a few more chapters. It takes a long time to prep a ship for a voyage overseas.