> by reading that the memory safe Rust language has and can cause undefined behaviour

Only unsafe blocks can cause undefined behavior. The memory safe portion of Rust that most program in cannot cause UB. If you use "forbid unsafe" then you can be assured your program is free from UB (assuming all the crates and stdlib you use are as well).

It still leaves me lingering in a space-time-continuum where I search for the safety of rational completeness, while inadvertently living on a Möbious strip.