Spending money on the poor

Q: I want to know about urdu word "nazar e muyyan", people sacrifice animals if they are ill, or calamity stricken and want to get out of difficulties.

Note: This is done without any commitment. There is another type of commitment that if I succeed I will spend such and such on the poor. I am asking about the 1st type. Does it have any relavance. If that is true, can I spend money because I cannot sacrifice an animal because of living in a foreign place?   

Celebrating Nabi (sallallahu alaihi wasallam)'s birthday

Q: Someone sent me a link and said that Nabi (sallallahu alaihi wasallam) celebrated his birthday because of what is stated in the link. Could you please calrify and tell us a way to explain to them why we cant celebrate Rabi ul awwal?

Did Nabi (sallallahu alaihi wasallam) fast on Mondays due to the fact that he (sallalallhu alaihi wasallam) was born on a Monday?