confused!!!

Okay I have been through this thread loads and it has been very helpful but I'm still a bit confused on who sign what papers.

Like who signs the annex form? I see one person said any vet long as USDA then another said it has to be the state USDA vet?!? 

Also in general is that form that the Aniphis 7001 forms the only ones I need? I have been on defra but it doesn't list form by form what all is required (unless I'm overlooking it)

I got the vet next week for my cat's annual check up and I want to make sure I have in order everything that is require of me when I do. My vet says they have dealt with international travel before but honestly when I start asking questions I get vague answers so its not very reassuring