Before we can help you, you need to explain what your goals are, and what the configuration is.
What does "standalone" mean? To some extent, every host (meaning every machine that runs one copy of the operating system) is standalone.
What is the system being used for? What packages does it have installed, and what services does it provide? What is its network connection (how firewalled, internal or external network, what ports are open)?
What is the reason for turning off some of these tasks, or slowing them down? Are they using too many resources?
A large fraction of the periodic jobs are there to warn the administrator of unusual situations, in particular related to security. Just turning off security because it uses resources is in most situations a bad choice.