Seems to me that the thing with the game recognizing constructions would be not too hard to do using just those i-button zones. The game can determine how splendorous it considers your construction by the number of tiles filled with non-natural wall (constructed, or smoothed/engraved) and/or the total monetary value of the walls and constructed furniture.
Randomly generated languages could work fine - you add a dictionary of banned words that the program checks against, and if the word is one of those it's not used. There are plenty of lists like this in the world, probably there are folks on this forum who could link to one or two good free ones.
You could also do just slight variation stuff, with perhaps a larger array of premade words and variant grammar rules for, say, different human kingdoms to pick from, leaving most of the language the same so they're more like odd dialects in the way that Jamaican or Ebonics or Scots are very similar to English but still recognizably different. Since there's nothing spoken, spellings can remain the same and accents need not be things that are particularly represented.
Regarding the corralling of your companions on shore leave: You could have a horn that you'd blow, and they'd all know "oh, he's blowing the horn, he needs us" or there could be some sort of a "meet back here in three days" plan, when you give them leave to mess around you say how long you're doing it for. And depending on their personalities, insufficient leave might cause trouble.