CorvusRuber
rkhunter was in the old solus thats how you know your not a og and you trying to start shit, but it is removed now due to it being depreciated in april 2025.
timeshift was also in solus, but it got discontinued and but got brought back to life, here it is: https://github.com/linuxmint/timeshift
clamav also used to be in the solus package manager, but later removed
sshguard is still in the package manager and can be used for brute force protection + firewalld which is also in the solus packaging
long passphrases is good to have if your on linux anyways so no one cant easy to guess and gain access, but ofc not too long as i mention 14+
disable unused services like openvpn since it is slower and old, wireguard more speed and modern. Since mullvad uses wireguard now, makes since to use less openvpn and no point to leave it enable
incase people want to run virtual machines from their actual pc for testing, trying out isos, or whatever they want
you seem to refering to "chatgpt" which no linux user should be using as they collect data etc, so no its not "gpt" and actually you can refer to