You've not shown that these properties don't exist. Nope, there is no reason to say this. But we are talking about what is true. Here you're referring to some absolute thing called The Truth. That's not relevant since I was discussing the truth of certain beliefs, which is something else.
Beliefs are true if their intentional targets are actual states of affairs.
Of course, all logical principles are trivial. No, the no entity without identity hypothesis is trivially true. So you claim. I'm not even sure what you mean by it. And having a perception is not an essential property of anything.