Qurbaani & Halaal Slaughter

6 shareholders distributing the 7th share of the qurbaani animal that was done for Nabi (sallallahu alaihi wasallam) equally

Q: If 6 shareholders put money together to make qurbani on behalf of Nabi صلى الله عليه وسلم with the 7th share of an animal, how will the meat of the 7th share be divided? Does it have to be shared equally between the 6 people same as the other 6 shares?

Asking an upright Muslim if his meat is halaal

Q: Is a person required to ask whether tasmiya was said over a particular meat when it was slaughtered if they are told it is halal hand slaughtered, due to the shafii's opinion that tasmiya is only sunnah? 

Also, if someone makes me something and I'm sure they don't change the way they make it to something haram, do I have to confirm every time I eat this particular food?