Qurbaani & Halaal Slaughter

Performing one qurbaani for the whole family

Q:

1. Is one qurbani valid for whole family living under one roof?

2. I have heard that qurbani is wajib but I have seen many aalim's videos who say qurbani is Sunnat-e-Ebrahimi. So if a person does not do it, its not a sin as its a sunnah act, is it true?

3. I do not earn and I am dependent on my father but I did have some savings, was qurbani wajib on me though I gave that money to my mother 3 days before eid as I feared sin. 

Conveying the reward of one's waajib qurbaani to many people

Q:

1. When a person performs one’s personal obligatory qurbani, for example one sheep, and intend donating the reward to the Messenger of Allah (sallallahu alaihi wasallam) or some other deceased individual, will the person performing the qurbani and the deceased get the full reward of qurbani?

2. In the above mentioned situation, when performing one's own obligatory qurbani like a sheep, can the reward of the qurbani be conveyed to multiple people (deceased or alive)?

Qurbaani of a horse

Q: In my country the price of goat, sheep, and cow is very expensive and it is very hard for us to buy a share in qurbani. I would like to know if we can do a qurbani of a horse and is horse a halal animal?