You can simplify all of the basic text responses by putting them into a table Instead of:
if (message.content === "foo") message.channel.sendMessage("bar");
Do:
var responses = {"foo": "bar"} if (responses[message]) message.channel.sendMessage(responses[message]); It may be more complicated for shorter stacks of if else statements but it is more efficient for large ones like the one in your code.

You can simplify all of the basic text responses by putting them into a table. Instead of:

if (message.content === "foo") message.channel.sendMessage("bar");

Do:

var responses = {"foo": "bar"};
if (responses[message]) message.channel.sendMessage(responses[message]);

It may be more complicated for shorter stacks of if else statements but it is more efficient for large ones like the one in your code.