Ctrl+click on "small guy" icon on scoreboard asks for engi already. The same with asking power and mass. Shift+click gives unit, or in case of power/mass, gives 25%.
Most of on screen messages I have seen are easy to understand/universel: ACU, nuke, antinuke, mavor, tml, eco, yellow ping for assist, blue for move and red for attack... People use multiple pings for more precision: Blue ping on unit (group) you want to be moved, followed by blue ping in place you want it to be moved to.
Official FAF language is english. I am not native english speaker, but as most players I respect to use of english ingame. Even when there are players from my nationality ingame, I speak english. As almost all other players (ecxept russians somtimes). And I dont use my langauage to make worst teams for other nationalitys. Or to bully them. Or to insult them.