Compilation speed isn’t that much of a factor of language as far as I can understand. It is more related to how optimization is done and how machine code is generated.
Also obviously it is about how fast the actual implementation of the compiler/build-system is.
This has drastically changed with "recent developments".
Iteration speed is everything now, if and only if you learn from the additional iterations.
Definitely not true. Otherwise we would have really fast C++ compilers and no one would ever have implemented hacks like precompiled headers.