What was the status of merchants during the feudal age in Europe? Did they, like peasants, serve/have allegiance to certain land owning lord? If yes, do they have different status or privileges from usual peasants? Or are they free from allegiance? If the latter, how did they become free from feudal lords who were generally powerful?
Merchants usually raised from the people of the cities, that is craftsmen. They usually did not originate from the peasants and as such had no allegiance to the feudal lords.
They also could originate from the city aristocracy, especially in Italy.
Merchants during the feudal system, tended to be Jews or other "foreigners." Lombards, Genovese and Venetians, (from the most entrepreneurial parts of Italy), and Greeks, tended to perform this function in northern Europe, Dutch (and other western Europeans) in Eastern Europe, etc.
Merchants were basically independent of the feudal system, being neither landowners nor peasants. As such, they were regarded with suspicion by the local elites. Their main selling point was that they had good connections with foreigners who could help them procure scarce goods. Hence, they were likely to be "foreign" (rather than local) members of a given society; most locals would not want to take on such a "foreign" role, at least at home.
Merchants weren't particularly well respected, but they were tolerated, and were allowed to live a bit outside the usual rules because they performed an essential (trading) service.