If we consider umas here as kindergarteners, CinGray Oguri naturally beats Pisu Oguri due to being a teenager (and thus has a bigger stomach to stuff food in). Worry not Pisu Oguri, you will become like that one day.
The Empire's FTL tech is less advanced that I've imagined. It cuts down time to move great distances, yes, but people on board still have to pass years.
Also, anyone still remember the part about "Holy Empire of Starveek?" Any chance the black-haired girl is a survivor from a previous Empire...
IIRC, they use flintlock muskets in this manga. That should be at least early 18th century, in our world it would be Great Northern War. So, sword fighting wouldn't be completely out of place, especially with those of higher standings. In last chapter, page 13, MC and colonel did say Marshal...