Let's decide for Dennis what he means by "broken" since, in all his glorious existence in truth and enlightenment, as he freely admits above he has no wisdom to share.
Let's say that when Dennis says "nothing is broken" he means everything is the way it should be; determined, caused. In this context, your reply:
Your first line is about what we usually refer to as ego, and is caused ("nothing is broken").Yet there's almost everyone who will list hundreds of things wrong in their lives, their suffering, and all their stresses to you.
Your lucky enough to understand the truth of the matters, yet they clearly have many issues anyway, being so unaware of the meaning making.
You can't deny they all think things are broken. If that's not true, then already their perspectives and efforts are wrong/delusional.
Your second line says to Dennis how lucky he is to know things are caused, whereas "they" have many issues since they are not aware of meaning-making. Yet, this meaning-making too is necessarily caused.
Then in your third sentence you say that it is undeniable "they all think things are uncaused". This is not quite true. Religionists think, for example, that god caused everything. Even the ones who believe in free will.
So, when you finally say, "If it isn't true that things are uncaused, then they're already deluded", it follows from your reasoning that religionists aren't "already" deluded but something else happens to them after this maybe to cause them to be deluded.
Yet, I don't think this is what you meant at all. Is it?