Russian has NO sound (and, naturally, no letter) "W". So I always transliterate it as V.
The last sound "ch": transliterating into English I use the "ch" which sounds like in "chair, change".
I don't speak Polish so I am not sure how sound "cz" and don't use it.
from Hebrew: if this is "tsadi" it is transliterated "ts". If it is tsadi', with apostroph, it is "ch".
there is no letter for "ch" in Yiddish, it uses "tet-shin"
you wrote: or Borovich). The latter usage seems unsound
Josef ASH, Israel