I agree with Miss Lydia- I'd try some duck soup first see if they are more likely to "eat" that before trying to tube feed. But, read up on tube fedding first if you need to go that route.
Sounds good. Once the shock wears off they most likely will get back to eating. They have moved locations it sounds like - so lots going on for ducks who don't like changes and easily get stressed out.
They are in shock. I would make sure the wounds are superficial.
Is the area fixed so that the weasel cant get back in? Did it happen at night while they were cooped?