All the sentences present correct information about SIEM, EXCEPT:

The object of a SIEM is to focus specifically on security$-$related information

A SIEM can also serve as a central log storage system and provide capabilities to query the information that it stores

Each SIEM will generate rules in different ways, but always with same complexity level.

the SIEM will do a lot of correlation for you so you don't have to pull a lot of data together yourself.