If someone can't have a conversation about an employment contract any more politely than "no verbal response" I have to wonder how they ever get hired in the first place.
The "must disclose any existing inventions or ideas to the company now and that anything not enumerated belongs to them" is what does it. Almost none of my offers have ever included such a line. Any company trying to push that does not deserve a respectful response.
I can have a conversation about the contract. But when the contract includes that, it is like being given a serious minimum wage offer.
So then you refuse that contract. If you are saying that the whole process is unserious then you're making a huge mistake since the legal system considers signing a binding contract to be a serious endeavor regardless of how you feel about it.
If someone can't have a conversation about an employment contract any more politely than "no verbal response" I have to wonder how they ever get hired in the first place.