Ceratin food halal

Assalaamualyakum muftisahib

I would like to know the hanafi ruling regarding the consumption of;

1) Crayfish

2) Oysters

3) Turtle/ Tortoise

4) Duck

5) Also, what is the permissibility with regards to the slitting of a ducks webbed
feet and thereafter slaughtering islamically and consuming it?
b) Is the salaah invalidated if while performing salaah one, due to excessive
weeping, swallows tears that have rolled down the cheek? (Hanafi)

JazaakAllah,