Just looking a few fine details of my wifes SV application....my daughter is dual citizenship. Should we present both her British and Thai documents (birth certs/passports) or just her British documents?

Also, do prior granted visas (2 in our case..student and visitor) give much leverage in the decision making process?

Just one more thing....is it me or are the folks at the visa center supremely unhelpful when you phone to ask what kind of documents to provide? Are there any British people there one can speak to?

As your daughter is British she needs no visa to travel to or live in the UK

AFAIK your wife just has to declare she has a daughter, no birth certificate or passports of your daughter are required . Your wife is also not expected to present a birth certificate either according to the VAF4 application form. Your wife's passport alone is proof of her citizenship and date of birth.

Having had previous visitors visas wont really help in the decision to grant a settlement visa. However those visas will probably be referenced during the settlement decision so what you declared on those applications must agree with your facts now. You are expected to give different assurances to those given with the visitor or student visas.

No idea about the attitude of VAC staff.