The Reish also can have a Dagesh and it is anyone’s guess what it is supposed to mean. The Samach and Sin are interchangeable, wwhich mean that they were meant to sound alike. The Tes and Tav don’t change. Perhaps there’s a difference there, too.
The Vav is only W at the beginning of a word when it is a Melupum. It is most probably the Veis that was changed. It was like the Spanish soft B, like blowing through a B sound.
Quf and Caf aren’t either the same. It seems like the Quf was similar to the C, while both went different directions through the years. We pronounce Ocean with a Sh sound but the Gemara spells it Uqyanus. Ceaser is Qaser. Most probably the Quf was like the second C in concerto, but from the back of the mouth and not the way we pronounce Ch.