[llarsson]

How slow does WP get if you load all of these onto it at the same time? How much would it resemble a Swiss cheese, security-wise?

[atknoz]

Load all of these? Why would you do that?

[Ayesh]

WordPress does not support PHP autoloading, and every plugin's main PHP file is included and run on every page load.

If you have a 100 plugins, that is WordPress core files + at least 100 files to run.

You will likely run into functions name collisions before you can run it. PHP also caches the opcode to the memory. So it's likely that you will hit memory or disk IO issues before you can do it.

WordPress has wp-cli that you can download plugins from CLI. Give it a try yourself, although I don't see the point of it.

[greggturkington]

Not sure why you'd do that, or why that's related. Caching would take care of any plugins on the backend.