Sorry, but the question regarding language safety is very clear-cut: either the language has an explicit model for memory safety, or it doesn't. FPC/Pascal doesn't. I am aware that it has some useful primitives which provide better safety than idiomatic C, but that isn't really what is implied by the claim that it is safer than Rust.

Similarly, C++ has memory-safe strings and arrays in the STL, with automatic memory management, allocation, etc., but it is also not "as safe as Rust." On top of that, FPC lacks any equivalent of the borrow checker. Automated reference counting is a good feature, but it won't stop you from writing race conditions. Borrow checking can, which is pretty powerful.

Using FPC with LLVM will indeed give you LLVM optimization passes, but it's got quite a lot of limitations. I'd probably opt to use the FPC native code gen.