User process resource utilization monitoring?

Yes, you can do this with Cacti. If you look at the Unix - Get mounted Partitions data query, it references an xml file path_cacti/resource/script_queries/unix_disk.xml, which references a perl script that actually grabs the data. You should get a good feel of the required structure from the pieces of this query. Once you get this part working, you can duplicate the graph template and edit as necessary.