I know that the term "Feudalism" is not the correct one, but I'm trying to reach it's general meaning aplied to this particular time.
How the administration on Italy worked on the times of emperor Louis II? Did the noble ranks that we see in later centuries (baron, count, knight, etc) already exist here, or have an equivalent? Was governance as ritualist and moralist as in the times of Charlemagne?
At the time of Louis II the kingdom of Italy was divided into comitati, managed by comites. These were appointed by the Emperor and not yet hereditary. The important ones went to the loyal friends or courtiers of the Emperor. There were marchioni, too, who were just more powerful than counts and sometimes in charge of some of them to defend border areas. Counts ruled their territories through gasindi or sculdasci, with military and police powers. Law was administered by judges in the city, but more often by scabini (illiterate, folk judges) in the countryside: these depended from the comites, too. Churchmen didn't hold powers yet, and were not often involved in administration. They could be powerful, though, just because bishoprics, monasteries and sometimes local churches were very rich. The king/emperor was still well respected. It's difficult, though, to say this was because of the time or because Louis II was a strong, charismatic king. There was little threat to his power, though, and revolts against him are not recorded. The king/emperor worked very closely with the pope as defender of the Church and its possessions, and of Christians in his lands and abroad. The queen/empress was very powerful too and she took often a diplomatic role. She was rich in lands and controlled most of the trade ports on the rivers of northern Italy, thus controlling the flow of goods through the kingdom.
Hope this helps!