fish fingers
No. Fish fingers, value or not are not suitable for vegetarians because they contain fish. Vegetarians do not eat fish.
Observant Jews do not eat crayfish.
Fish that have fins and scales
Does a buffalo eat chicken wings? Fish don't have fingers!
Jews who keep kosher don't eat fish wihout scales (Deuteronomy ch.14).
Yes.
Eating human fingers (dead or alive) is called cannibalism and is not approved of. Eating fish fingers are fine.
No, monk fish has been determined to be non-kosher.
depending on how big they are yes
At the time of the Mishna (200 CE), rabbis deemed it meritorious to eat fish on the Sabbath and Jews became accustomed to eating fish at festive meals. Gefilte fish, which has been called the quintessential Jewish food, is an especially popular fish to serve at the Passover Seder meal.
Beef, chicken, fish, lamb, venison. It is worth noting that there is no magical food that Jews replace pork with, it's just that they do not eat dishes made with pork and therefore will eat different dishes than non-Jews who do eat pork.