A4-6210 with build in GPU has TDP of 15W. There is no point to optimize anything it is seeping power already. may be try to use tlp to limit max charge level of the battery ( i’m not sure is you laptop is supported). You can play with governors too, but I personaly will not bother. You obviously need multiuser.target but not GUI.
ICINGA/NAGIOS? you can even feed data already collected by Prometheus to it if you want.