A memory safe language may force you to think about memory safety, but it can also work as a straightjacket that makes it more difficult to think about other security issues.
I've not found this to be my experience; if anything, working in Rust has freed me to think about other aspects of security in my project since I don't need to spend all my effort applying extra tools to find segfaults. Do you have an example?
No, because the memory safety part comes at a cognitive cost.
You may be right if you're talking about a GC'ed language, which gives memory safety and at the same time frees up the developer's mind. But if you're talking about constructs like borrow checkers then they do add cognitive load that is perhaps better spent elsewhere.
