hi,
yes station_deux_roues is a mistake.

the output of charging_station:output is documented in the wiki as the maximum power delivered you can have in the most capable socket, it is not the installed power output. 
people are often confused about this, we should find an other tag to describe this, because the charging_station:output is very useful to find a capable enough station at once.

about infos for socket being absent, it is useful to know that the info has been checked and that there is no need to double check, don't you think?