Why did rome need consuls and what were their job limitations?

The Roman Consul was very similar to the presidents of today's democratic societies: They were elected for the time of one year, appointed by the Senate but elected by the people of Rome, in the assemblies ''Comitia Centuriata''; to avoid excess power, the Romans simultaneously appointed two consuls, so that each consul had veto power over the decisions of the other. The power of the whole empire was expressed through the Consul, for they were Heads of State, commanders of the army, they called the Senate, and they also presided over it; were present in popular assemblies and had the power to execute their decrees (just like the presidents) and when their time was over, they were appointed governors of the conquered provinces.

Farm land would be my guess