There is no single plugin that can do all these three things for you. You may need to install multiple plugins and follow various procedures to achieve your goals.
Blocking spam is probably one among your three goals. Akismet Anti-Spam plugin from Automatic is great tool. It can process up to 50,000 comments in a month for free.There are also many other free and paid anti-spam plugins available. Apart from the plugin, you can also consider implementing a commenting system like Disqus on your website.
Ensuring the security and performance of your website is a comprehensive process. It starts from your planning stage right from choosing hosting.
But still there are many plugins that will help you to protect your WordPress website and increase the performance to an extend but that wouldn't be perfect if the foundation of your website is not good. So, I would recommend you to hire a web developer with strong expertise in WordPress and web technologies to revamp your website. There are also may web design companies specialized in website redesigning to improve performance and security. You can hire them to revamp your website and make it perfect in terms of security and performance or you can get their consultation.