Is there logging for any of the dom0/domU command line tools?
Does dom0 produce logs for qrexec, systemd, RPC calls?
Yes. Examples from journalctl:
Nov 15 09:42:39 dom0 qrexec-policy-daemon[2014]: qrexec: qubes.OpenURL: untrusted → @dispvm:fedora-38-dvm: denied: denied by the user /etc/qubes/policy.d/90-default.policy:53
Nov 15 09:45:55 dom0 qrexec-policy-daemon[2014]: qrexec: qubes.Filecopy+: work → @default: allowed to disp3240